What are the rules and regulations specified by FAA about the code of conduct of flight crew members?
And, are there any rules which specify behavior of passengers with crew members?
The FAA is responsible for safety regulations and standards, not for code of conducts or courtesy regulations for interactions between flight attendants and passengers. Flight attendants are bound to certain behaviour only by their employer and their code of conduct, additionally to any national law that prohibits insulting others or harming them otherwise.
Flight crew members are bound by the rules as specified by the airlines. Additionally, pilots are bound by the rules decided by the Air Lines Pilots' Association, International. These are called code of ethics, and you can have a look at them here