That is the one thing about ROTC, you must be commissioned before you earn your pilot slot to UPT. So if you don't have the quals to get a pilot slot, you will be doing something else for at least 4 years. If you go the OCS, or OTS route, you can apply for that pilot slot before you get commissioned. If you don't get that slot, you don't owe Uncle Sam anything, if you do, you will go onto to OCS, which is in Pensacola for Navy folk, and get your officer training there. After commissioning, then you start flight school. But don't let any recruiters fool you by trying to get you to sign up for a NFO slot telling you that you can transition to pilot, it won't happen. For your first and second choices, put 1.) pilot and 2.)pilot, and nothing for 3.