1. All robots currently in the game are going to be removed and replaced by those built in the robot workshop. Pneumatics are purely notional at this point. They are way too powerful and responsive, but we haven't put any time into the pneumatics system yet. Expect all pneumatics to be completely replaced with a new system at some point in the future.
2. We do not have permission to add robots from Robot Wars or BattleBots at the moment.
3. Making robots quicker is a matter of gearing, balance, friction, motor selection. All of this is up to you. We are attempting to make the game as physically realistic as possible. I recommend looking at http://runamok.tech/squid/newtorquecalc.htm to see how motor selection, gearing, and weight affect acceleration and top speed.