My 2c: they don't seem very well written overall (what happens to the current undead if you animate a new one with Corpsewalk? It gets destroyed, or remains but is now uncontrolled?), and Vanishing Act seems pretty overpowered (at-will Swift Invisibility, assuming "vanishing" means becoming invisible). It could stick to providing concealment for instance.
With that said, I love the idea of adding new Reserve feats.