One point I'd like to make is, when you first get to the academy, you don't have any social life off of the yard. Until parents weekend or later, you aren't going downtown and going to clubs. Even then, because of age, that is even rare. So there isn't really too many scenarios whereby someone would know you are gay or straight until they got to know you and you told them so.
Like I mentioned, is was almost a year after I got married before many I worked with even knew I was married. And considering I am straight, it's not like I was hiding anything. It simply wasn't an issue that was brought up. The first time many met my wife was at a squadron Christmas party.
Point is, at the academy, especially the first 6 months, the only way someone would know your sexual preference, religious and political views, etc is if you tell them. And by then, if you've established certain friendships, chances are that won't change.
I have been reading this thread with some interest for a while and figured I'd chime in on this.
Like the current cadets pointed out, you LIVE together at USAFA. Without "flaunting", however you define that, if you are out, chances are everyone will know pretty quickly even if you don't tell many more people than your basic roommate. The argument that you have control over that is a little unrealistic
Having been at USAFA at a time both right before and right after the repeal of DADT, I think I have an interesting perspective.
First, I can say that before the repeal of DADT, I knew at least a fairly high number of cadets who were gay. A couple I knew well (hornetguy) and others I saw in maybe one class. I didn't ask, they didn't tell me, and if you ask me to pinpoint how/when I "found out" I couldn't. My point here is to reiterate the point that others have made that USAFA is a small school and it isn't as simple as some are making it out to be. Even if you don't "flaunt" it, chances are everyone will know.
Now, after the repeal of DADT I noticed very little change other than some very happy cadets who could now talk about their SO, invite them to graduation etc... most of the general cadet population was happy for them and while there are some that I am sure had a problem, they never shared and it never cause friction (in my personal experience)
USAFA is an incredible mix of backgrounds and upbringings, but despite that, I never noticed a problem come from race, religion, sexuality or political views.
So my answer to the OP is don't worry about it. Be yourself just as you would in any other professional environment (when doing things like classes/interacting with upperclassmen) and when you are "off duty" or as close as you get during 4 dig year, just be yourself and don't give it a second thought. Good luck!