Assorted thoughts
1. Self, why are you constructing an elaborate headcanon about David Steel's troubled relationship with BDSM? No1curr. If anyone wants to read about him at all, which they probably don't, they want Owen/Steel shōnen-ai with traditional seme/uke roles, not Steel/Penhaligon or whatever crazy obscure shit you're going to come up with next. And anyway you do not have time to write "Five times David Steel's D/s relationships turned into total car crashes (once literally) and one time he lived happily ever after" until you've finished all the WIPs you've promised people, which at this rate will happen... oh, around the time of the next general election. And you do realize that writing a fic in which four of the main characters are named David is a recipe for disaster, right?
2. I'm on an Alan Garner kick at the moment, and something has just occurred to me: I wonder if in The Owl Service Huw got the boys swapped.
I've never understood why he brings Gwyn back and spends so much time trying to get him to help Alison, because it's totally counterproductive- Gwyn is Lleu, so he can't forgive, he can only escalate the cycle of violence. It's not Gwyn's fault, really; they're all trapped by the narrative. Lleu has to go for the kill and Gronw has to die (or stand around letting people insult his mom, whichever), or the cycle can't complete. Possibly Gwyn needs to be physically present for the denouement, but given that Bertram died alone up the mountain during the last round that seems unlikely, and clearly asking him to de-owlify Alison is a complete waste of time.
But the logical assumption for an outside observer like Huw would be that Gwyn is Gronw. On a shallow reading it's Roger and Alison who have the preexisting relationship into which Gwyn intrudes, and Roger is the crueler of the two boys. And if Gronw runs away the entire valley is stuck with Blodeuwedd in owls mode until he comes back to die. It would make perfect sense for Huw to run after Gronw to fetch him back- and it puts a pretty nasty gloss on it, too, because he's retrieving Gwyn so that he can be killed. And last time that involved actual physical death, not just people saying cruel things to one another. I suppose we don't know how much psychological damage the children did to one another- perhaps Roger goes on to commit suicide- but it seems to me they got off pretty lightly, this cycle. Although maybe that's because Gwyn came back and ended it so quickly, and if he'd actually succeeded in leaving the valley the cycle would have dragged on for years and the charge would have built up until it could only ground itself through Roger's death.
3. Also it would be fun to give grown up Gwyn a cameo in something as a Welsh MP, but I can't because he hasn't got a surname.
4. Further to Item 2, I've been thinking a fair bit about Wales, and magic, and what Neil Kinnock thinks of it, and I reckon he puts it into the same category as brightly colored socks. In London magic is a human power, and controllable, and safe, but in the Valleys you immediately stumble into all this old pagan mythic stuff that's extremely powerful and highly dangerous and tends to work through you, rather than the other way around. (See also Susan Cooper, Jo Walton). I suspect that for Neil magic is one of those things you want to keep outside your nice, clean kitchen, because it's shifty and unreliable and not really working class or Christian, and decent hard-working people have no truck with it. Actually, Tom Driberg aside I suspect this is the view of Old Labour as a whole. Which is rather awkward for Neil's young wizard spin doctor, who wants to throw everything they have at the Tories, including this. (The Tories, of course, are completely sanguine about it- Disraeli was a great wizard, and upper class kids with the gift learn magic along with all those other traditional English skills like Latin and cricket at Eton and Oxbridge. Tebbit's an anomaly, but he's another one like PETER BONE- so powerful he doesn't need a formal education.)