Two Things

Graphic apps and word processors need two features:

1) When you highlight capitalized text, the caps lock button should turn on. When you hit it, it should de-caps your caps. Hitting caps lock on highlighted lowercase text should capitalize it. Selected mixed case letters should go all caps. Ctrl+caps lock should put it in title caps.

2) Ctrl+Z is great until you run into using a paint brush or eraser, there should be a slider for those times that let you undo until the part you fucked up.