I busk every day at school but not for money, so I would say "no" busking doesn't have to involve money k? lol
You do not busk anywhere. The act of busking is defined as performing or entertaining in a public place for tips only. Busking is an honourable profession in Errope but is looked down on in the U.S.
As a busker, I can (and have) gone anywhere I wanted to and made a very good living. We are the ONLY people that can do that. If you aren't working in a public place for tips you are not abusker so don't try to pass yourself off as one.