Re: #5
No, broadcasting is verboten. Amateur radio is for two way communication. Broadcasting is when you are constantly transmitting and not bothering to listen, because you are occupying the carrier frequency with one's broadcast.
As to what currently prevents it, other amateur operators will report it to the FCC (If they don't bother to triangulate the source themselves and send a HARM missile that way). If someone is being an obvious prick, the FCC will confiscate equipment and shut down offending transmitters.