Do you get in trouble if you run away at sixteen and come back at eighteen?

yes quite a bit of trouble! at that age, you will have police and people looking all over for you the whole time because of the very fact you are not 18 yet and you could get killed out on your own! put yourself in your parents shoes! although it may seem like there are quite a bit of conflicts, nothing is so bad that you must cause them to worry for years about your death. however, if you MUST get out of the house, it is legally ok for you to go stay with a family member, such as a grandma, aunt or uncle, for protection until things calm down at home!