Just some things as they come to me, not just for Austria.
For all the Germans-
Germany is a rule abiding guy, as we know- when it comes to training he's disciplined as fuck and while he's screaming at you to run laps, he's ten times as hard on himself- not that he particularly considers it hard. It's just what he does. In fight situations he's wary, prepared for dozens of outcomes and can react on the fly /but/ he's an honorable fighter, for the most part. Not above being pragmatic but he doesn't really fight dirty, and he doesn't always expect the enemy to either. He was more naive when he was young, it's less of a problem now. But say you got him in a duel or a boxing match, there would be Queensbury rules all up in that motherfucker and if you break them he'll break your nose. I think, though he'll fight fairly as long as you do, if you start fucking with the rules he'll lose his scruples a little and just wail on you. He's not experienced with swords the way the others are but modern weaponry is his element, and good ol' fisticuffs is just plain easy for him- fun, too.
For Girlmany it's not much different. Germany would hesitate to fight a woman (or anyone clearly weaker than him, but it's a safe bet most women are considering his musculature), but if he can see she's a threat or a match for him he's not stupid enough to hold back too much. He's a pretty equal opportunity fighter. Girlmany on the other hand is powerful and just as highly skilled and trained, with the added bonus that she doesn't have his size advantage over most people, and she's obviously female, therefore she has no need to hold back or be chivalrous at all. On the other (other) hand, while she can be aggressive, she's generally just as strict about fair play if not even moreso. Neither of them go around picking fights, anyway. I like to think she's a kickboxer or something else leggy. Women have stronger lower bodies than upper, and all that. (The girl with the murderous thighs...)
Austria just plain doesn't like to fight, doesn't like physical exertion, derives little pleasure from any of it. He's excellent at the actual /moves/- champion fencer if he's only going through the motions (anything involving hand to hand combat is right out, though, he can put up a basic fight like most people could, but hell if he's any good at it; on the other hand, he's been known to tackle certain people when really riled up), but he lacks the fortitude to keep up that kinda skill in an actual battle. More to the point, he lacks the composure, ironically. He can't think so quickly as he usually does when there's a sword flying at him. He's a great strategist but he needs time. Back in the day he was a lot better (especially his teenage years, oddly enough, he beat Turkey effectively enough) but he's rusty as fuck now and couldn't keep it up for more than a little sparring- unless his life literally depended on it, which might prompt a more fervent effort. He prefers swords in general because it's ~classier~ but he's decent with pistols and rifles, at least on the shooting range. It takes precision and he has that in abundance.
Fraustria is an odd case of being even less willing to fight than he is, but far, far more physically violent if she feels she's in danger. She's pretty small and she reacts to threats in a more hit first, ask questions later manner. Outside of that though she's as nonconfrontational (well, physically speaking anyway) as Austria. On the other hand, she trained harder than he did. She's a little harder, a little more disciplined, and a lot more used to scrapping with her Prussia. They aren't above brawling on the floor. She takes pain a little better than him (no offense guys but...women really seem to take pain better) but in fairness, he can suck it up and take quite a lot of punishment (and...they both...have been known to enjoy it a little) stoically. You learn to do that when you've been smacked around all your life, pfft. Austria is obviously stronger, but Fraustria is stronger relative to her size than he is and she gives more to a fight. He's hesitant, he's chivalrous to the point of being effectively useless against a woman (and most men to be frank) and he takes a while to realise, oh hey, this is serious, I should probably stop fucking around and trying to do fancy manoeuvres. Fraustria's guilty of those too though, but since she's smaller than pretty much anyone there's like no one she'd hold back against. She might not be that strong but she'll resort to anything in self-defence- honorable as she and Austra like to be, if it starts going to hell, he'll panic and she'll start biting people.
Prussia is easily distracted, easily bored, a crybaby, whiny, overexaggerates pain, the works...except when he's in a real fight or a training session. In training, he's incredibly disciplined albeit in an unorthodox way- Germany follows the manuals, Prussia follows his own curious internal guidelines and rules that he's bulit up over the years. but he also treats it like fun, he enjoys training in a way- as long as it's scrapping and not pointless laps or something. In a real fight, he's ridiculously good, when he gets down to it. Swords were his thing when they were in fashion; as soon as guns came about he switched. He's a little jack of all trades, not quite master of any, because he picks up whatever's gonna dominate the battlefield at the time instead of sticking to one type of weapon or style. He can get serious and strategise like no one's business; not quite the crafty, slow planner Austria can be but he can think up whole new strategies on the fly if needs be. Since he's thinking of so much at a time and he's naturally slightly inattentive this can go awry, but he's fairly good at just winging it if it doesn't all come crashing down on him. He's arrogant enough that he can fail to see how anyone can outdo him, so if you're good enough, you can really take him by surprise and floor him. There's a chivalry to him and a kind of honour, but mostly he's incredibly pragmatic. He cheats all. the. fucking. time. Not that he regards it as cheating, it's just good sense to him.
Prusschen is just as good, just as serious, just as strong- while I see a difference in the Germanies' and Austrias' physical strength I legit think the Prussias' are a relatively even match. Prussia is not that big and Prusschen makes up for the height difference in ruthlessness. Prussia might be a good sport and hold off a bit depending on his mood, the situation and who you are, Prusschen won't. She doesn't aim to kill or even seriously wound, she's not incredibly violent by nature or anything, but she's dead serious when she wants to be and she /hates/ to lose. Even more than Prussia does, if it's possible. She works herself harder, she has more to prove, or feels like she does. She could kick his ass, frankly. Strategy wise she's a genius but she tends more towards a careful pre-planned strategy than he does, in warfare- ina casual sparring session they're both pretty loose about planning things. If Prussia gets hurt he shrugs it off then whines foreeeeever after the fact. If Prusschen does, she just grins and flaunts the scar. (She whines to Germany in private.)
There's a pacifistic nature to the Germanies despite them being the stronger fighters. Just a combination of history and personality. Prussia's the most fight-happy and Austria's apathetic at best, until he's very angry or very threatened. Or defending someone else, because sometimes chivalry is handy. Even Fraustria is something of a gentleman in her way, and Prusschen too- they were knights, after all. Prussia too but it's buried deep under there. Germany and Girlmany are modern thinking and awkward and don't hold with such romantic notions. Prussia strongly disapproves of men who hit women and still has- or acts like he has- some outdated ideas on the whole business. Austria is a gentleman but for him, that includes respecting a woman's right to get herself bloodied up should she so choose. He's been with Hungary long enough to have a very healthy respect for women who like to get physical- and unlike Prussia who would just die, and Germany who'd feel kind of weird about it, he has no problem whatsoever with letting a woman fight for him and protect him- providing she can handle it. He'll fret himself into having vapours if someone so much as gets a little cut, however, but that's just what he does. Prussia has a mildly panicky nature about that kind of thing, too, Germany's the calm one in a crisis.
Austria places sentimental value on his past weapons in spite of his dislike for using them. He names them and keeps them shiny and displays them. He hoards everything so there's always a bunch of that old military stuff at his house. Prussia switched a lot so there's less attachment but he can tell you his favourite model of sword or gun without having to think about it. Germany secretly names his gun and refers to it as she but mainly acts like a pro soldier when it comes to that kind of thing, and is obviously nitpicky about safety and cleaning and so on. Good at repairing, using and tl;dring about all kinds of modern weaponry.
If any of them are drunk all this becomes moot. Of all six, taking into account their strength and attitudes, Germany is the most reliable to have on your side; Prusschen the worst to have as an enemy.
For just Austria-
STINGY. Austria is typically described as stingy. I think it's more complex than that. In canon, we see him pestering others about frugality, patching Germany's underwear and buying expensive cheese to impress Switz even though apparently he eats like a pauper at home. In the next breath canon is telling us he bought an /entire orchard/ for a particular kind of fruit, for a particular kind of jam, for /one cake./ What the fuck. He wasn't really trying to impress anyone there, he just did it in the way anime rich kids do. So basically it seems like he'll spend stupid amounts on frivolities but not on necessities. He's wealthy- really wealthy- and he still has that luxurious, decadent aristo mindset in a lot of ways. But even as a kid, he would be yelling at Spain for overspending. One standard for him, another for everyone else. He's extraordinarily hypocritical, but we knew that already. He'll take anything that's not nailed down- not a thief but as he would put it, he's pragmatic, an opportunist. If he can make money he will, but he also likes to treat himself (and occasionally others...he's painfully cheap about giving people things unless it's a lover, apparently.) and I'm of the opinion he would gamble, also...he has a strange relationship with money. Think of French aristocrats just before the revolution. At once broke and makin' it rain.
In his youth, he was first very tight with money- because he was a good boy and he was trying to build an empire, not crash it. As he got a bit older, he was...kind of bad. (Part of me really wants to play teen!Austria at a slightly older stage than Archduchy, because he seems like he would be /fun./) Bad like adultery and debauchery. So his finances were a bit more all over the place. Empire had to be more austere but still ostentatious. After the wars (and during, of course) things were really stretched. His natural caution was amplified by debt and rationing. And it left a mark, so now he's still pretty reluctant to spend. His house is this massive beautiful thing but in the lesser used rooms it's just dust and hoarded treasures. He doesn't renovate it. He's in the habit of keeping things lest they be destroyed- his portraits and jewellery and instruments are investments, in case of emergency, before they're historical artifacts. Realistically, there's little chance of him being involved in such a terrible war again but it's at the back of his mind sometimes. His hubris was absolutely shaken, he learned his lesson thoroughly. He's an arrogant guy, personality wise, and it's the kind of arrogance born of insecurity, but he's nothing like he was as an empire. As proud as he is of all the power he had and all that he achieved, he looks on everything pre-ww2 as youthful stupidity. His true glory days were when he was much younger, HRE era before everything went to hell.
So yes, he has an odd relationship with money, competing natural tendencies making him somewhat schizophrenic with it. He /likes/ it, a lot, and he likes to hoard and save and make more. And he loves to chastise others about it. It pains him to spend money on boring things like the bills or, you know, basic food, but he'll drop stupid amounts on a violin or this one restaurant that he likes and justify it to himself somehow. 'I won't buy anything next month...!' lol yeah sure. (I do that all the time.) Sometimes he sits around and counts money like as a leisure activity. He absolutely flaunts it among people he dislikes, or fellow wealthy people. (Don't let him go shopping with Monaco or anyone like that.) And oddly, he's quite...generous? Not financially, but with his time. In canon, people can get him to do some weird stuff for them, like that whole stripping in the street business. RP wise Julia regularly manages to make him spend time and money on her. I think he has a kind of host instinct. He likes to entertain and cook for people etc. even though he complains outwardly, because he feels appreciated and it's an ego boost. Also, even though he spends a lot on his ingredients sometimes because he makes fancy Viennese things, a lot of Austrian food is really rustic so he can do amazing things with hardly anything.
He is very much an Impoverished Patrician sort of character, not really impoverished but certainly not the kind of absurdly wealthy aristo he used to be. But he's not used to being a plebe, y'know. Austria doesn't even strictly have aristocracy anymore so he can't really be one but it's heavily ingrained in him. I kind of think he might have gone by von Habsburg earlier on, actually. 'von' is the aristocratic style that people don't use as much anymore and I can see him using it, and that name, on occasion because he feels entitled to it. von Edelstein? idk. I think nations have a lot of names anyway for different purposes and they probably mainly use their country names. Then again, those change too, so it must be hard to be totally attached to any name. (The oldest, proto-Germanic version of Roderich is Hrōþirīkaz, and the Old German is Hrodric. It means something like great ruler. Which is at once apt and not apt. Silly Germania.) But back to the subject at hand. I'm always hesitant about gifts from Austria. At heart, he wants to give people stuff sometimes because he cares about them, but he's so hesitant to spend that he often just makes things for people. But it's not very special to cook for someone when you basically make them dinner every day...for someone important he'll waive his stinginess temporarily. (Prussia and Germany, you guys get a cake. Deal with it.)
Quite aside from spending money, he likes to make it. He doesn't really work as such beyond politicking and bureaucracy. But he does a bunch of stuff that makes money, is fun, and steers clear of the taxman. Busking! Busking somewhere no one he knows will find him, for tourists. That's less 'I'm so desperate for cash I'm playing Beethoven's 5th on the street' and more just a little escape. Concerts! That one is more professional, he conducts or plays in an orchestra. It's more of an actual job, I suppose. Songwriting! Under a pen name. Pays really well and he basically uses the same four chords as every other song writer because people today don't know music. He deplores it while profiting from it. He doesn't really make any money off his other hobbies, like cooking and such, but he could if he wanted. Sometimes he dabbles in art dealing, sometimes he gambles a little bit. Sometimes he buys and sells property. It's whatever takes his fancy at the moment. Being rich, lazy and lonely is sometimes boring. He misses when he could buy and sell small countries. I suppose his existence is a comfortable ennui a lot of the time. He wouldn't go back, but being a small republic will never compare to controlling a continent. Without getting too dramatic and psychological, micromanaging his finances and meddling in his family's lives is kind of a substitute for what he used to do.
Really, his tendencies remind me some of the upper class in Britain. They aren't even necessarily wealthy anymore but it shows in the tastes and behaviours they have. If they have an old stately home, it will be worth millions but in a state of disrepair. Their clothes are respected designers or tailored but they're old and worn. Aristocracy is a state of mind, not a bank balance.