I would suggest seeing a lawer first and asking them what steps one should take. I know that it can be a long process and can be expensive. I would suggest figuring out another way to leave your parents or guardian other than immmancipation because it is difficult to acuire unless there is a very good reason: physical abuse and if the guardian is doing something that is not for your benefit, like spending thousand of your dollars on something for themselves.
Immancipated
Yes, a 17 year old can be emancipated from parents. It is a timely process thru the court system though. Unless you're in harms way I would recommend waiting a year until you're 18.
Not necessarily, there is more to it than that. Claiming can be more than just living arrangements, its about support. If he's financially supportive then deductions can still be legally made. It could also possibly depend on any state laws that might apply where you live.
You must check with the local court house in your state to find the age of maturity. It is usually 18 years old, to enter into a legal binding contract. Unless the minor has been legally emancipated he cannot enter into a legal contract until he reaches the age of majority for the state, which is 18.