WASD or controller sending movement signals ranging from 0-255. WASD would be able to send just 0 or 255 and controller would use the whole range.

Let's assume we have the ball send signals based on being hit or being in the goal and appropriate Nodes will listen to those signals.

Boost indicator and jump indicator is all you really need for gameplay. Score counter up top. These would just be the defaults and in the settings we could implement UI modifications. The indicators could be moved around.