>>96164903
Prestige Classes : Shadow of the Demon Lord style. Every class has 5 levels. Base classes have no requirements, prestige classes do.
Feats : Each feat has its own isolated effect with some scaling to it. Feats might interact with other feats, but no requirements between them.
Skills : Not sure. On one hand, my first thought was something more open ended. On the other, not having specific skills like the different knowledge X means not having specific mechanics tailored to them.
Probably break them down into categories and have different classes able to choose at least one from each category? Something like that.
I'd keep the skill points since I enjoy the feel of having some level of granular control.