Check with his insurance carrier but my guess is no. Unless you are a spouse, you wont be allowed to get on the policy. Now, if you were pregnant with his child, the medical expenses related to the pregnancy would be covered.
That would be cool probably he can
No, even with the every changing laws, put a "boyfriend" or "girlfriend" on your health insurance policy. To do so is against the law. Insurance companies are intollerant to people who try to scam them. Therefore, if caught, you may go to jail. You would need to decide if that person is worth going to jail over and also losing your job over.
You can put who ever you want on your insurance policy. You don't have to be married for this. Hope this helps, talk to his insurance company about it, and they will most likely tell you the same thing. Good luck.