Click the "Next" Arrow to switch the motion from WASD to your cursor. 0 and 1 switch your Weapon System from a single unit to two side units. 2-6 in single unit changes the weapon type. 2-5 in dual unit changes the weapon type. (No Bi-Frag variant.)
I am aware of the glitch allowing you to change the weapon system and type in mid-fire but that is unavoidable until it is implemented into a completed game.