Spriting doesn't need layers.
I tried spriting with layers, and everything became over complicated.
You don't have undos in real life drawing, you just erase. You dont ussualy work with anything terribly big when spriting so you can just erase like everyone else.
The pallete is the only thing you're right about.
EDIT- @odin-And the space is two pixels high. It's as wide as the zoom select box.