Protection of employees is weaker than anywhere else in the US. The Northern Mariana Islands have been accused by the US Federal Government and various other organizations for enslaving foreign workers (particularly from China and the Philippines) and immigrants in sweatshops and prostitution.
It can be as low as 18 or as high as 21 depending on where the child lives. In Delaware, the age of majority is 18. However, almost all states allow the child, a parent or a guardian ad litem to write to the judge and/or petition the court for modification of the original custody agreement.
There is clearly a misunderstanding about children choosing who they want to live with. In Texas, children do not get to choose who they want to live with. Section 153.009 of the Texas Family Code does allow for children to have a voice on the subject. The law allows for a party to request for the judge to confer with a child. Once a request is made for a judge to confer with a child, the judge must talk with children 12 years of age and older and may talk with children under the age of 12. Therefore, the law allows for children to state their preference, it does not allow them to choose.