Ill have a crack at it

Power: 2 S28-400 Magmotors @ 36v

Dont use the heading Power because that is too broad and a miss used term for what your explaining. Use Drive. 2 x S28-400 Magmotors @ 36v is fine, but maybe you want to explain a bit about the gearing and wheels. Im guess you dont know how to calculate the ratios. Looking at your stats, the robot is invertible and 200mm tall, so Im assuming your wheels are 200mm in diameter. To get 20MPH with those drive motors and those wheels, you need 9:1 gearing.

Batteries: 4 NiMH
This is about as good as saying My robot has 4 motors. You need to clarify what batteries your using. If you dont know, ask I generalised through your stats and I believe you mean 4 x 36v NiMH packs, in either the 3000mAh or 3600mAh capacity. With the 3000mAh this will give you a minimum runtime of 3:52.

Weaponry: A giant front-hinged flipper powered by a 5kg CO2 canister, running 2/3rds up the front wedge. This gives WR enough power for 30-35 flips, and to launch an opponent (on top of him) from the middle of the arena to a CPZ and quite possibly over the fence.

A lot of talking, but no evidence to back it up. Your system seems like your basing it roughly on the power of WBC, which, with the combination of other things you have in the design, you probably wont have the weight for. You might want to look at other vapourbots like Geforce and Spinverter for well designed flipper systems which would fit into your design.