No
pregnant
No, it is not OK for a 12 year old to be a 16 year old's girlfriend. A 12 year old is far to immature and much too young for a sexual relationship. A 16 year old who would take advantage of a 12 year is breaking the law.
If you both have parental permission.
Yes
No. The 16 year old is a minor while the 20 year old is an adult. The adult can be charged with rape of a minor.
No.
yeah
A car.
Yes but they can not have sex until she is 17.
yes it is
With his parents' permission he can live anywhere.