Did you think about using the vi (or now vim) keys for movement (h,j,k,l)? I have an extreme amount of muscle memory for these keys. I'm kind of surprised that no one else mentioned this as working from the home row is a big reason to use vi as an editor.
It looks like you could change the h, j, and k keys with MultiMap. Then would have to put 'copy' somewhere (maybe i). It would be nice to get a vi-friendly mappings/key covers (for the seriously old geek users). I usually like to learn default settings, but may have to give in to 3 decades of vi use in this case.
Looks like a really cool product! Thanks for making it.