That's right. I never said "not serious". I said that you seemed to be less than enthusiastic. That's pretty normal considering that they came to you first. It's not as if you are hell bent on being a Navy officer at any cost. If you were too enthusiastic, I'd be worried about you. That would indicate that you might have been too easily sold. When someone offers you a good deal, it is a wise and prudent course to investigate and think on it for a while. Being slightly skeptical, as you are, shows that you are weighing the possibilities. You are much les apt to be disappointed in any case than those guys who log on here and say stuff like "I'm going to enlist Navy Nuke so I can get to be an officer. My recruiter told me that all nukes get to be officers, ...etc., etc."
As far as the contract goes, they will do what they say, if you do what they ask. NUPOC is absolutely NOT a back-alley scheme to lure you into the enlisted ranks by promising you a commission that they don't intend to deliver. They have every intention of pinning gold bars on your collar, but you have to do your part to earn them. Anyone you might have heard of who didn't make the cut was probably looking for a free ride. I wouldn't worry about any medical/physical problems either. If you are not fit enough to become an officer, chances are that you won't be fit enough to be an enlisted man either.