My bigger picture reply to you, Laker, is to do your best to really familiarize yourself with USNA or the other service academies before you apply. At a minimum, try to go on a CVW at USNA, and take advantage of any opportunities you might have to talk with midshipmen and cadets at the various academies.
My feeling was always that the people who were most unhappy/disillusioned with USNA were those that either (1) thought (incorrectly) that it would be MORE like a typical college; and (2) thought (also incorrectly) that it would be nothing like college/American society, but a "Knights of the Round Table" of dedicated warriors in training.
On the first point? Very different from college. One obvious difference is gender imbalance -- 80/20 male to female is not typical. Moreover life in Bancroft is not like life in a college dorm. Room inspections, door open policy, prohibition on drugs and alcohol and sex. Does it mean nobody has ever done drugs in Bancroft or been drinking or had sex? No. But it's just nothing like the environment you'd see if you walked into a dorm at UVA or UNC or Harvard or Yale for that matter.
The second point is also important. It's not a holy brotherhood of warriors (or even sisterhood). Some people are not that into the military aspect. WHAT?! You say. At a service academy? Well, yeah. Some are from military families and going to USNA is a "tradition" that they wish they could have broken but they didn't. Some are Division I athletes there mostly for the sports. More than a few saw USNA as the best way to get a great and affordable education. If you focus on the other midshipmen who don't live up to your ideals you will be disappointed, disillusioned, and maybe even quite unhappy.
Turning to the "is the party culture like college" question, when mids (and, I assume cadets) are most like "typical college students" is on weekends. People drink. They drink to excess. Some people do drugs (not that many compared to those who drink, given urine testing, etc.). People look to hook up and have sex. Maybe USNA has more of a sense of a distinct "weekend party culture" because of (1) the tradition of mids (sometimes teams) having houses in Annapolis (which the powers that be are trying to crack down on, it sounds like); and because (2) Annapolis is a small city with bars, etc. that are easily accessible on foot from the Yard. West Point cadets party too, but there's not much right outside their gates so maybe they have to spread out more, do more with using weekend passes? From USAFA types I knew, there were definitely traditions of having apartments in the Springs that people went to on weekends for partying. Put young people of the opposite sex in the same place with lots of alcohol and a desire to blow off steam and some bad things will sometimes happen. This is universal. It is not being ignored or accepted as inevitable within USNA or the military at large -- they are working on it.
There are also plenty of people at USNA who don't want to drink their brains out every weekend. There is an active Christian community and lots of service oriented activities. If you want to make a life like that at a service academy you can, but realize others will take a different path. If you remain very troubled by that and can't learn to make your peace with it, you will have trouble with military life itself and the young officer's job of taking care of your men and women (who are young and often do dumb things).