Very true. Blackmail is of prime importance in light of National Security. Best not to have any secrets when you have a clearance.
For some yes, but overall I'd have to disagree with this one. Many militaries do not segregate based on sexual orientation, and they've experienced no problems. Israel is a prime example of one.
Sexual orientation is of lesser importance IMHO than cultural upbringing. Inner city recruits and "redneck" recruits constantly butted heads in BT and in Tech ("A") School. One of the earliest lessons for a recruit in any service is to teach that we are all Americans first and foremost, on the same team. It takes some longer than others to accept that fact.
This is probably one of the biggest stereotypes that gay people face and they probably simply laugh at it. Just because someone is gay does not mean they walk around lusting after anyone any more than heterosexual people do. It's called "self-control". Completely heterosexual men constantly talk about women in the workplace once they find themselves in a "safe zone" where they can, i.e. around other guys. Women do the same thing. It's called biology. ALL the gay men I have ever known never chased me around, crazy with lust.