Yeah, if you're going to move your hands, it's important to move your whole arm and not bend at the wrist, as you say you're doing. (I used to bend my wrist to hit the backspace key; I got a keyboard with the backspace key in the middle and it made a huge difference.) But my recollection is that you're supposed to do as little moving of the hands as possible. Wikipedia seems to confirm my recollection: http://en.wikipedia.org/wiki/File:FingerHandPosUSA.gif

I was lucky enough to not know VIM when I switched...

I am a QWERTY touch typist and I do not, nor do I twist my wrist to hit those keys with my ring or middle fingers. Rather, I move my hand to the correct position. Touch typing does not mean your hands have to remain in one location, unless of course I am misapplying the term.

Likewise. I am a touch typist in that I can type while the keyboard is nowhere near my field of vision, I may not be a touch typist by any more specific definition (I certainly don't consciously follow a particular approach). I will move my hand to be more or less centered on whatever I'm doing, only twisting it when I need to hit several keys at once (which seems likely to be necessary with any keyboard).

Incidentally, the reason I did not switch to Dvorak long ago was that my vim keybindings work much better with a QWERTY layout and I was not willing to remap those.

This is the kind of thing that I'm worried about. Changing over any particular application is undoubtedly doable. Changing over everything is undoubtedly a headache, and in some cases may not even be possible (flash games, say, not that I play a lot of those).