I often have a lot of questions, but unfortunately have to sleep when the stream is live. Can you show your current modal setup in Emacs briefly in one of the following streams, please?
Did you do anything else except for changing your editor to relieve some pressure during the day, like doing different tasks for a while or taking more breaks? I feel like programmers need to have the same mindset as athletes concerning RSI. You can be reckless and work very fast, but then your career will be short. :( Anyway, it's tough, and I feel your pain.
PS: I have something similar to you, I think, but in my right hand. The more I use the mouse, the more I get a numb feeling in my hand on the side of my pinky, and ring finger, which is indeed related to the radial nerve as opposed to the (more known) median nerve.
There is something called "Evil Mode" in emacs. This is pretty much vi/vim commands for emacs. Vi/Vim is a modular text editor while emacs is a non-modal text editor. I am guessing he is either using this or something very similar.
In theory, next week the entire stream will be me making a modal mode for 4coder that is the same as my Emacs mode but without all the Emacs bugs, and then switching to it, so you'll see the whole thing (and I'll be giving the code to Allen so he can release it or whatever he wants to do with it).
But no, it is not evil-mode, nor is it even remotely like VI.