No, the child is legally responsible for themselves at the age of 18.
No, he has not been a child and your responsibility since he turned 18.
No. Not legally responsible for the 20 year olds actions. However, if they have signed some kind of legal or loan document with them they are responsible for that. .
Yes, unless the child has been emancipated, or is in the care of the state or another guardian.
Both parents
yes.
Yes, they can. Parents are responsible for their minor children. They get to decide where the child lives. They are also responsible for the child's welfare in any case.
Not once they are adults. It is often done to help the child get started in their lives.
Not on taxes no. The parent the child lives with has the main right to claim the child. But if that parent can't or doesn't want to then the other parent can
If they are the child's legal parent yes. The only way that they might be unresponsible is if the other parent had sole physical and legal custody. If they have joint custody but the child lives most of the time with the other parent they are still responsible.
The second parent or closest relative
I would like to add the noncustodial parent lives in North Carolina. The child is attending college in South Carolina. She is at the age of 18 years.
It depends what age .