I've run into a similar issue - I can't rebind "J" because it is fixed to ToggleFreeCursor, and cannot bind to "N" because it is bound to "Open Shop."
I'm left handed and re-bind all my keys from traditional WASD to IJKL and the surrounding keys. This has worked for me in every previous Valve game I've played, and hopefully it can work in Deadlock.
I'm going to dig around the config files to see if this is something that can be changed manually rather than from the game UI.