GIMP has some really goofy controls, I can totally understand not being able to get used to it - especially if you have used potato chop before.

My best tip to you PS -> Gimp movers. Or anything at all. Forget everything you know and start learning again. Start learning the program as if it's a totally different kind of thing. Don't just assume you know what things do. As with anything: familiarize yourself with the layout, controls, menus. Baby steps. When you're done with that, then take the bigger steps towards what you need.