Simply mouse is always at hand, so you can do everything with one hand. I just do not know what other functionality can be "hung" on the wheel, and views would be convenient (just IMO).
The role of the mouse wheel is to change the size of the brush, assigning it to do 2 different tasks would make it confusing and probably difficult to use.
Well I like to keep my left hand on the keyboard. Also, C and Shift+C changes view too. There's also spacebar for pause, H for hiding info, S for stamps and Ctrl+C/V for copy/paste