if my designated broker who I work for in real estate says they don't want me to do business with someone because that person was rude to them once can they do that since they are my designated broker or can they not since I'm a independent contractor?

does a independent contractor still working for a firm even though they choose the time and where they work?

where must my license be held ? the main office or if i work at a branch office that specific branch office!! thank you - real estate