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.
nothing.
no she can not
NO! That pedifile
No
If he has a girlfriend, then you need to take it one day at a time and move on. Some things are better left unsaid to eliminate awkward feelings between friends and jealousy from the girlfriend.
yes.
Yes. An 18 year old CAN move in with a nineteen year old. If it was your girlfriend or boyfriend. NO husband or wife.
Minors can only move with their parents consent.
No.
There are no laws about dating, only about sexual contact.
Only with parental consent.