Currently in keymapping, controls all need to be bound. It's more of an irritation than actual problem, but I'm sure I wasn't the only player that had their mousewheel bound to a particular control, like power use. With U17, that changed to alt-fire for weapons, something I rarely use.
It was a mess trying to get my controls moved around to the point of having some button I don't use be alt-fire since the game would not let me out of the keybindings menu without assigning a button to everything. I first assigned a button I never used, which apparently was assigned to something else I didn't use... repeat this for a good while and I think you get the point.
Please change it so we don't need to bind every option, action, control. Some of us may want to try out a config first then come back and assign a button/key, and some of us may not want to use that action at all. I get that the overall idea was to make alt-fire work better, it was a bit frustrating to have to move around key controls just to find what keys I use least then reassign them all until the game was happy that a bound everything.
