It's amazing how fast you can retrain muscle memory by disabling certain keys. It's frustrating for about half a day, then kind of annoying for a day or two, and then you've completely retrained yourself. In just a day or so!
However, I like to fiddle with the cursor while I'm thinking. Might be just me. I don't like feeling like I'm completely constrained. It's nice to casually move around when I'm pondering something deeply.
When I'm seriously coding though, I almost exclusively use move forward/backword by word or expression, and then use ace-jump to arbitrarily jump to specific points (http://www.emacsrocks.com/e10.html). I use Emacs of course.