I would also agree that class doesn't matter - just play what you like.
Regarding mouse, I would suggest to try out the new Razer naga 2014 (was on sale for $50 yesterday).
It is a bit bigger than the 2012 one and the buttons are separated out and are uniquely shaped.
I personally use the 12 thumb buttons with the shift+ and Ctrl+ modifiers for a total of 36 binds.
Other than that, I just use the Q,E,R,F,C,X,Z keys for miscellaneous keybinds.