Well I still believe as I said as long as you live in their home you abide by their rules. Legally he is still considered a "child" and therefore his parents are responsible for him. Now I agree with you that once he is old enough to go out on his own then that's what he should do if he is not happy there.
I know this is not the popular stance here on this thread but the "child" should not be the one making the rules around the house. Yes some parents can be too strict but they seem to let him do pretty much what he wants in others venues. Don't you think he should comprise some as well? I don't know him or his parents and I don't know how things are around his house but he seems to have it pretty good from what he has said so far.
I too have known people that grew up in extremely strict homes and most of these people went on to become good successful people when they left home.
As for respect, I'm a lot older than you probably and we were always taught to respect our parents after all they do everything for you until you are grown and leave home. You don't think they have earned your respect after all that?
Don't mean to rant just my two cents worth.