Thanks tai, good idea. The original Keyboard Settings window ignores right-click; you clear a key there by dragging its icon off the keyboard. We liked your suggestion, so we're adding it: right-clicking a key will clear it and send its icon back to the tray at the bottom, and dragging will still work too. We'll mark this fixed once it's in the game.

This is in now: right-click a key in Keyboard Settings to clear it, and its icon goes back to the tray at the bottom. Dragging it off the keyboard still works too. Thanks for the suggestion, tai!