Same thing I was thinking about the braces. I would just remove them; the kitbot frame is plenty strong by itself. They're just added weight that pose the risk of interfering with the chain.

Also, I would suggest protecting that vertical electronics board. If a trackball falls on it as it is now, it's toast.

If you need more speed/torque, consider buying 2 more CIM's. They're very cheap (I believe only 25 bucks). Gear down and you'll have the same speed with much higher torque, or vice versa.

Besides that, looks great! Great job with the battery placement.