[ChrisA]

As far as I know, it is not illegal to move outside the boundaries as long as you don't touch anywhere outside the field. I do believe that if the robot touches any crowd members, that would be considered outside of the field and the robot would be dq'd.

I'm pretty sure if part of a 12' arm came outside the boundaries it would probably hit the judges' tables, announcers' tables, or referees, before hitting the crowd.

Also, a 12' arm should be fine stability wise, as long as it has a strong enough counter-weight.