Oh, ok. :)
So in any other game (literally, every game I've ever played), when you hover your mouse over a button and it says (R), it means, "press (R) on the keyboard instead of clicking here." Maybe you *could* give people the hotkeys through that interface instead? (as well as left/right mouse button clicks) So that display I showed with be "(mX)use class ability (a) use skill" and so on.