Teen Rights Laws in Indiana

I live with my girlfriend and her two teenage children in Orange county Indiana. Her son is 16 and has decided in the last month that he should be allowed to do as he pleases. He thinks he should be able to come and go as he pleases, smoke dope, move out, get a job, quit school, etc, etc. Reason is falling on deaf ears. I'm wondering if anyone can give us advice as to what we can legally do to keep this kid in line.

The neighbor next door has advised him that he can file a petition with the court and move out. This sounds like a lot of baloney. He's also convinced that he can runaway and not be caught. What can we do if he decides to not come home when he's told to come home? What can we do if he decides to stop going to school? His mother is at her wits end, his father has given the sage advice of, "if you wind up in jail, don't come crying to me" and I'm left referring.

Any advice would be welcome. Her 14 year old daughter is watching all of this with interest to see what she can get away with here shortly. Thanks in advance.