A couple of suggestions for accessories:
Give us the ability to save accessory location/size/angle data separate from costume saves (maybe the favorites tab?). That way we can add an item to multiple costumes without having to re-tweak them for each one.
Create a separate accessory section for face and body, each with their own accessory slots. I'm finding that a total of four is not enough; if I want a hair extension, glasses, and earrings, I only have one slot left for body accessories. While you could just expand the total number of slots, separating them into face and body might give a better balance.