My advice is to go into one of the non-rated career fields and bust your ass. Get yourself into an aeroclub and befriend one of the old heads and have him teach you everything that he knows. Apply to pilot on all the boards that come up while you're eligible and I'll bet you'll get picked up within a couple of years. I am a NAV turned Pilot but I can tell you I was lucky and got in before the force shaping stuff and the "to many pilots" BS. Looking at it now with only one shot at a board and less than 20% selection rate for pilot there is no way in hell I'd take those odds, but I'm not a betting man. Good luck.
You may be lucky but I wouldn't tell people to turn down a nav slot. Once you turn down ANY rated position, even in ROTC, you can never apply again. I was a nav before becoming a pilot and loved every minute of it. Like I have said on other post, BEING A PILOT DOES NOT MEAN YOU ARE THE BEST THE AIR FORCE HAS TO OFFER!
You can put in an application but cannot start UPT until you have served 2.5yrs as a nav. I had a Capt in my class that did 8 months. Some people think that navs are second class aviators. The only thing we don't do in JSUNT is get stick time, stp. We learn about weather, instruments, approaches, flight rules, airspace, all the regs, etc. We actually get more training on flying the friendly skies b/c we have sims that allow us to do so. In UPT our flights/sims were no more than 1.3. In UNT the flights/sims ar 4.0 and you are a**holes and elbows the whole time until you get pretty good. Then they throw new sh*t at you. We learn about ICAO procedures and pratice them in UNT. In UPT you may read about them for 10 minutes. I always wondered when I was a nav why new copilots had no clue about the flight rules, approaches, STARS, etc.
Then going to UPT I found out.
There we learned EP's, systems, and EP's. I understand why they want you to learn all the systems and EP's for flights. The sims could have at least tried to prepare pilots for most of their flying, in international airspace. Copilots have no clue how to fill out an 1801. Nor do they know have to give a position report. Yes, pilots in the Air Force know how to fly a plane, but I'm here to tell you it isn't as cosmic as many want to believe.
Sorry to get on a soapbox. I don't want to see anybody turn down or not apply for nav b/c they think it's below them. The nav flies just as high as the pilots and looks down at all other non-rated officers who regret not putting in for the backseat .