I used to be like that.. pounding the space bar all day. Not any more, it's all eyes up data entry and commands, and the keyboard is only for text entry. I've even made peace with the ribbon!
Anyway, I've now paired the nostromo with a M570 trackball. So now I have 2 busy thumbs, plus in any window I can scroll up/down with right hand and roll up/down a list with the left hand scroll wheel. Nice way to tie your brain in knots!