Looks like it's possible to replace the standard keybindings in OS X text widgets. The standard ones are patterned after the set in the EMACS text editor. Yes, it's a standard set, but it's unintuitive to say the least for someone whose fingers have been using WordStar keybindings for 30 years.
Fortunately, there's a standard way to remap it all, and it looks like it's possible to even do WS-style key sequences. The details are documented here, with additional documentation here.