I like this idea. I thought of doing something similar with the first three, but the others sound interesting to. I wish 3e had went this route from the beginning.
I don't. I came back to D20 from GURPS after getting tired of systems trying to express everything in terms of skills.
There is no perfect set of rules. There is only a ruleset that is good for what you are trying to achieve. Having combat as a skill achieves one thing and is suited for certain styles. Siloing it off as a restricted ability achieves another and is suited for other styles. Before I'd move combat attributes into skills, I'd have to first decide to play a game where the ability to swing a sword was no more important (and maybe even less important) than any other skill.
Sammael's design has a certain elegance and he does a good job picking his skill set both in breadth, size, and balance, but I'm not convinced I need it for any game I envision. Though, based on the skill he shows in crafting the skill set, I'd be interested in sitting in on the game he wants to run.