Remember that there won't always be 8 players. It's hard to figure out a good balance so that the game will be fun for 4 players as it will be for 8 players (currently have that problem in my game...)

As another Idea, when you try your steering code (and I would really use the mouse... sorry for stressing that point, but I think it makes a huge difference), you can try aiming and shooting at stationary targets in the level to test if the steering's good enough...