Thanks for your prompt reply. I'll deal with these point by point.Wow. That's a big post. I'll have to give some of it more thought, but there are a couple of things I can clear up now.
1. In the OTL, Edward III was able to walk a line between making the nobles happy and giving away his power so it seems it can be done if you're careful. For me, with how overbearing Edward I was I can't figure out how Edward and Piers in the OTL DIDN'T end up being cleverer.
2. Scotland is broke at this point. In the OTL, they had to continue. But once Edward II made his overlordship theoretical, Scotland has no real reason to fight.
3. The Holy Roman Emperor helping Edward II conquer France and Isabella's brother all dropping dead within 15 years of each other with no male heirs both happened in the OTL. I just took advantage of it.
I'll post more after I've had a chance to think.
1. Temperament is the reason? More importantly, Galveston and Edward are roughly the same age. While he isn't technically Edward's guardian, he's acting very much as one, which is rather implausible.
2. Technically, the Scottish War by this point had devolved into a guerrilla war where the English could never win without significantly more Scottish support than they ever achieved. While Edward's conciliation makes war unnecessary, it is still possible. This doesn't mean that Robert will immediately revolt as soon as Edward marches south of the Tweed, it does mean that the Scots will be able to jockey for greater autonomy and power, and represent a constant running problem for Edward (at least until France supports the Balliols).
3. The Emperor was doing this OTL to blunt the rise of French hegemony, which was the point. The HRE's interest is to prevent other western European powers from matching it in power and influence, not to favor one particular power over another. In TTL, the strategic imperative would be exactly reversed. Moreover, Edward TTL unchecked would become far more powerful than OTL's France, and so the HRE would be even more desperate to halt its rise, far more willing to lock itself into a negative-sum war of attrition just to maim it. Also,I don't really see why the OTL HRE supporting Edward against France would have any relevance to the TTL HRE supporting France, at least to your line of argument.
Of course, it is your TL, and it's fine if you ignore these. However, if you deal with these issues in a good way, this TL has the potential to go from promising to great.