Of course it is!
extremely
no of course not -.-
Sure, it is illegal in most states, though.
Yes
If the 17yo is a runaway, yes. It's illegal to help a runaway from home.
i'd google missouri+sex+laws for that one
Assuming they're absent from home without their parents' permission, absolutely they're considered a runaway.
The parents can request the police to return the runaway to their home.
It is not illegal for a 13 year old and 17 year old to date/hang out together in Missouri. If it were every high school would have to close down. However, just because it is not illegal does not mean it cannot be prevented. As minor, a 13 year old girl can have restrictions placed on her by her parents or guardians.
You shouldn't run away in the first place, and yes it is kind of illegal.
In Missouri, the age of consent is 17. Therefore, it would be considered illegal for an 18-year-old to date a 15-year-old. It is important to abide by the laws regarding age of consent to avoid any legal issues.
yes, you have to be 18 for USA laws