Defensive options, blocking goal or taking from other robot
I'm guessing no, but can you knock the pin or cup off the opponent robot, with a piston punch or just a piece of your robot sticking out more? When ramming the other robot on normal defense, I'd assume you could have a piece that sticks out more for that purpose.
Other question can you cover the hole for the cup or put with a piece sticking out from your robot. I suppose that would leave the other goals open, although it would be another option besides hitting the other robot.