Rodrigo Istalindir said:
Mayhap Monte and Mike's new book will quench your thirst.
But, in stock D&D, I think you might end up with everyone looking the same. The same feats already get taken over and over again -- I don't know that having more feats would change that. Plus, you'd have to find something to give the fighters to differentiate them, and also deal with power creep.
Feats are fun, though.
People keep talking about everybody taking the same feats.
Maybe, with the relatively narrow selection in D&D3[.5]E--though the only feats that were consistently taken in our D&D3E game were by characters going for the same niche/schtick. The closest to an "everybody wants it" feat, IME, was Point Blank Shot. And, even then, none of the spellcasters, and some of the warriors didn't take it (my char, frex, didn't really do ranged combat).
But with Arcana Unearthed, even given more feats per character, i don't think we'd see much overlap. Heck, i've got two characters both going for the stealthy agile light-fighter archetype, and i don't think they've picked a single feat the same. And these are characters that keep stepping on each others' niches, to the degree that it worries me as a GM.
Anyway, other than screwing up the relationship between ECL and CR, i don't see any problem with increasing the frequency with which feats are gained. And with a system for actually calculating ECL and CR, like i gather Grim Tales has, that would become a non-issue.
I do like the idea of providing a bit of structure to the feats gained, however, in this case. In addition to possibly splitting feats gained according to type (combat/skill/social, perhaps), another possibility that comes to mind is splitting them according to prereqs. So, at odd levels you can only take feats without prereqs, while at even levels you can only take feats that built on your existing feats. My thought is that this might balance deversification and specialization, forcing some of the former and allowing some of the latter, but limiting hyperspecialization that can make balance tricky to maintain, and limiting hyperdiversification, which can make niche protection difficult. I haven't actually looked at how many feats do or don't have prereqs, and it might need some adjusting of feats.
Another quick thought: you might need to increase prereqs for some feats. Any feat that has lots of feat prereqs, but few level-dependent prereqs (like skill ranks or BAB) would now be available at much lower levels, which might not be desireable.
Oh, and on fighters (and other classes with bonus feats): so what? They still get more feats than anyone else, even if everyone gets more feats in total.