As long as your child does not have a vehicle with them ever when at school the many insurance companies allow for a large discount due to the fact that the child is not a regular driver. They are still a member of your household and should be on your policy in case they drive when at home or may drive when at home.
Yes you can.
It depends on the rules of your state. In Oregon, yes.
If he will be driving the car, then he should be on the policy.
It is up to the policy holder. When I had to stay with my aunt for a long time we kept my insurance in my state of origin. It works too when you have a child in college and you are in another state. Contact insurance agent or insurance company to verify.
The best college car insurance is offered by companies such as State Farm and All State. You can get more information about college car insurance policies at their respective websites.
Perhaps, (as an example) you own two cars, and have one child in college in one state, another in another state, then yes, the policy will be written in the 'home state'.
Let the state take care of it
No, by law in the state of Georgia if a child willingly moves out of the parents home, him/her gaurdians are no longer responsible for that child.
File Contempt of Court.
No possible.
Depends on the laws in your state and the child support order.
SSD Child Benefit stops at age 18. Child support beyond high school is dependent on state laws. see links