It's possible that I missed how to do this, it's late and I'm tired. But ... it would be helpful to be able to clear a control setting, to make it a (none) directly, rather than by removing the existing control and re-assigning it to something else. The fewer controls I have to mash with my stubby fingers, the better. :)

In your controls configuration menu, pressing backspace will clear the currently selected keybindings.

and so it does. I'll amend my suggestion to suggest that this be noted on the control configuration screen. :)