Read the constitution my friend.Off the top of my mind-- anything that is not accepted by the FDAand any form of abuse or stealing.
drink and drive, drive without a valid license, murder and theft
It is not legal to work in this country if you do not have a green card and you are an illegal.
No, it is unlawful everywhere in the US.
Busking is considered to be free speech but may require a permit in your local area it honestly depends on the time of day and noise level if they are complaints the police can try to charge you with...