During fights:

left click (to target at times)
right click (used to turn, used with left click to move tank)
middle click (mapped to auto follow)
awsd (to move rest of team-mapped to a joystick G13 driven by left hand)
IWT mapped to G13 key
Next Target mapped to G13 key
0-9 on gaming mouse used in conjunction with shift/ctrl/alt keys mapped to G13

During a boss fight I probably use.... 15ish of these typically.