Yes, motorcycle's have the same rules as an automobile.
You have to study the local rules. I think 49cc motorbike is not allowed on the highway.
of course..every state requires aCLass M license to operate a two wheeled vehicle
it depends on your state laws you should go an look up the laws in your state most states you don't need one like South Carolina and Florida but again it depends on your state.
Yes! Please see all the requirements and procedures in the motorcycle manual (related link).
In the UK, yes they do. Insurance is also compulsory.The wearing of a crash helmet is also a legal requirement.