[Al Skierkiewicz]

Boy,
You take a few days off for the holidays and look what happens. Here are a few answers for you...
The battery can supply more than 400 amps for short periods of time when fully charged, limited by it's internal impedance, life cycle and state of charge.
The 120 amp circuit breaker is capable of more than that for periods of less than 10 seconds but must be derated for increased temperature. (the breaker is a temperature only controlled device as are all of the self resetting breakers.)
Yes the rules allow more than one 120 amp breaker but only one can and must be used for all power to the robot. That makes the use of a second breaker downstream redundant and provides a second source of failure and added series resistance.
As pointed out before, only one Victor and one breaker per motor. Using two on the same motor is asking for trouble and will not pass inspection. You may feed two Victors/motor combinations the same PMW signal if you choose by using a "Y" PWM cable. This rarely works as intended but is a quick and easy solution to some problems.
Self resetting breakers and Victors are also capable of significant overcurrents for short periods of time without trippping or damage. Don't depend on the overcurrent handling to make up for deficient designs.
The 50 amp Anderson Power Pole connectors can handle the extreme currents because their rating is based on continuous current at 50 amps. The temperature rise in a two minute match is usually enough to prevent any damage. I have seen melting with these connectors but it usually was a case of damaged contacts caused by the use of alligator clips on the charger to connect the charger to a battery. I always suggest that teams change out the clips for a mating Anderson connector on the charger(s) for best results.
There are two limiting factors in electrical system overloads that prevent excessive damage in First Robots. 1) The resistance encountered in normal wiring and electrical design places a significant resistance in series with the battery which will limit maximum current. 2) The Robot Controller will mute all PWM outputs during any period of time when the main power supply falls below about 8 volts. Maximum loads on the battery will drop the terminal voltage below this point, shutting off motor control and thereby reducing current. Should the backup battery also be discharged or fail, then a delay of several seconds will occur while the RC reboots and reacquires communication.
Hope all this helps, good luck this season.