In reply to the OP.
As some have said, it is possible to get a VP nomination, but only if you applied for one. As for a superintent nomination, there are very few of those, and you'd have to be a candidate that the academy really wants. Part of the No Brainer club I've mentioned in the past.
The fact is however, without a nomination from some place, you get get an appointment. That's just the way it is. No way around it. No exceptions.
As for a prep school offer, that's tricky. The prep school slots are for individuals who are usually deficient in one area making them not competitive up front, but the rest of their application shows tremendous potential. Usually the deficiency is in a particular class, your act/sat, or similar. In other words, most people are "over qualified" and won't get a prep school slot. Some think the prep school is where the sports teams put all their applicants who are athletes so they get an extra year to train in the sport. Most athletes either get a direct appointment like everyone else, or they get nothing. So basically, if you're sitting with a really good gpa, have good act/sat scores, passed your cfa, medical, and have an excellent application, then you're probably over qualified for a prep school slot and won't get it.
But not knowing your application, I can't say for sure. I will say however, if you received a navy nomination, and you're fortunate to receive an appointment, and you truly want to serve in the military as a commissioned officer, you should really consider accepting that appointment. You have much better odds. Best of luck to you.