The whole design is way to narrow. With the high speed gear motors, turning will be near impossible with the drum on.
The motors are geared way too low, any wheels bigger than three quarters of an inch will bog the motors and fry them. Consider this gear motor instead.
Faster does not equal better. Unless you're going drum to drum, excess speed is actually a detriment, as the drum will struggle against even flat sides. The motor you've listed is already spinning at over 12000 RPM, unless you have a single toothed blade, it will struggle to gain any bite against an opponent. Consider a lower Kv motor, or gear down the motor somehow.
You should consider a Car ESC, which will allow your motor to reverse. Can be a life saver for an invertable drum.Also consider this radio, its much cheaper and has been shown to fail safe too(You will need a programming cable, however).
Your parts list looks suspiciously like Sgt. Cuddles. While its fine to use some parts with some consideration, you need to understand why he used those parts. Also, I need to point out that Sgt. Cuddles performed very poorly at Robogames.
You really, really, should not make your first bot a drum. Drum bots are not easy to design or construct. The first bot is already a hand full and adding a weapon makes the whole thing worse, really think about starting with a static wedge(The Fingertech Viper or the Rovparts Ant1 are very simple and comparable in price), then once you understand how it all works, you can add to it with more vicious weapons. It's really worth starting with a simple bot, just getting the thing to start up is in self an adventure.
Really? We must have looked at it from a wrong perspective! Funny thing is, that motor is actually similar to what we found, but it has ~10,000 rpm from what we were told.Noted. The custom teeth we came up with is a bit heavy than your average drum teeth, and we are taking that in consideration. Safe zone is 8,000 to 10,000?It is, and he doesn't explain why he uses those parts, just how they connect. I am aware of his performance, and I watched his matches, along with Saifu's matches as well. See what works and what doesn't.