As far as number one goes, I think the patient has the right to privacy unless it is clear that they are putting someone's life in danger by repeatedly engaging in unprotected sex. I think that you can't just assume that they are irresponsible - you have to give them the benefit of the doubt. And you may not know someone's partner(s) in every case anyway, and you can't go running around the country hunting down every recent contact. But I know that when you have knowledge of them putting someone's life in danger through repeated reckless behavior you are obligated to warn that person.