Depends on the laws where you live and what the age of consent is, 16 or 18. But I think it will be likely. 17 is very close to 18 and at 17 you are more of an adult than a child unlike a 12yo. The 17yo should've known better.
yes
Yes, a 12 year old may be able to be pregnant.
if a 3 year old can then so can a 12 year old
yes a 12 year old can get a women pregnat
yes
yes
Yes. That is possible.
Yes, I don't think you want to be a 12 year old mom!
The answer is no. Swallowing semen can not get you pregnant.
No.
If a 12 year old has gone through puberty, he could get any girl pregnant. He can get his sister or any other girl pregnant.
If his balls have dropped
It depends on if the 12 year old girl is fertile, And if the boy can ejaculate sources: I'm a teenager.