I played duke nukem 3d and quake2 a lot years ago, and got into using the mouse for movement.

I can't get used to the WASD style of play.

I use the 1 - = keys for my main abilities, with my most commonly used abilities on 1-4.
I hit the tab key for targeting with my pink, when I don't care who I'm going for - or use the mouse when i want a specific guy.

My healing is all on numeric keypad 1-6.
I have the bar above 1-= mapped to F1-F12 and have more rarely used abilities on there.

My hands move all over the shop, but it seems to work. To a certain extent the shaman suits my playstyle
(or maybe I play like this as it suits the shaman )
You have to stand to cast so I can switch the mouse to targetting if need be or triggering some ability or other.

I used to use my nostromo - the arrow dpad on that would also allow me to move - so I could switch seamlessly between mouse and thumb movement.

I've got a g13 now - but haven't set it up for my team yet. I like to get a setup that I know I can operate without additional hardware before I map it to the g13.

Apologies for the essay.