So far, there isn't an in-game way to remap controls. I've been playing with just the keyboard, using the arrow keys to move, E to interact -- when absolutely necessary -- and, when in battle or when moving text along, using Space instead of E. I haven't tried using the mouse much, I honestly don't feel like I need it, since I'm moving with the arrow keys and not WASD, thus using my right hand, which is what I usually move the mouse with.
I know this isn't the ideal setup, and I didn't particularly answer your question, but maybe you'll find playing "my" way more suited to your needs, at least until Airship Syndicate releases a patch that allows for key rebinding (if that's even a thing they're considering).
Maybe someone more tech savvy than me can direct you to some settings file you can edit to remap key bindings... I don't usually mess around with those.
It's more about the back button being ESC... or am i being stupid and not knowing another easier to reach button?