Interesting ideas, especially the last sentence. If I ever make this into a TL, I think I will go this route.
I think I've hinted at it before, but how would the Netherlands fair as the northeastern corner of France? Would we see anything analogous to a Dutch revolt?
Possible but by no means inevitable. After all, the Duchy of Burgundy itself was a predoominantly French state, and I think most of the upper crust spoke it even in the Netherlands.
If there's a bust up, imho it's more likely to be about religion, as OTL. If the Netherlands gets markedly more Protestant than the rest of France, you could get an eruption, but it's a big if.
I'm not sure, but I think that if a Protestant rebellion still happens in French Netherlands it would be seen more as one of the religious conflicts that France would face at that time rather than a war for independence.