I guess I'm a hybrid. I use number keys 1-4 mostly, but not the others. Not as reachable as the ones above WASD. I tend to use those 4 keys for my main attacks and I found that when I'm healing, I'm not really moving around that much so I can use the mouse for those. On some of my other characters, I found some abilities aren't used that much, so I can trigger them w/the mouse and save 1-4 for most often used abilities.
Though I'm not getting a fancy mouse w/multiple buttons I can map hotkeys to.