In the opposing vein, as an Emacs user the best configuration I ever made was to rebind C-x C-c to execute-extended-command instead of kill-emacs. It was way too easy to (even accidentally!) kill emacs with a sweep of a finger. And I probably use a few hundred execute-extended-command calls for each kill-emacs (which I now have to type manually as 'C-x C-c kill-emacs' - no problemo). A similar optimisation was with t…
I think gnu screen has the right idea here: ctrl-a.
And you say z is close to control - does that mean you use emacs without shift lock as control?! (I mean sure, still closer than b...).