It's been added!
Checked it, a couple remakrs:
When I change the command for A to bind it to Q, it prompted me saying Q was already assigned, but it doesn't look so.
Also, adding a link in the main menu to key rebinds (and even options) would be cool.
Oh and also a "Resume Game" option in the pause menu so that we don't have to press Escape.
Haven't played much but interesting work you've done. I'll come back to it later. :)