As a dear friend says, "You can choose your friends, but you can't choose your relatives." That does not mean you have to have any contact with the relatives. Of course if you are in a small geographic area, it might make for some drama. But nowadays (given some of the families I've seen) it is not only worth it, it is the only way for folks to survive and prosper.

You are not responsible for your blood. If you have done the "family" thing and people try to pull you down/take advantage/hurt you, then you must do what is best for you and yours.