Fulfill the terms of your contract, do it honorably and give 100%, then do whatever you want. If being a lifer was a precondition of becoming a pilot or an officer, it'd be a 20 year contract, not 8. Not everyone can stay in, by design. There's not enough room for everyone to stay the distance.
As long as you don't take our training and fly for Osama bin Laden, do what you want after you're done. I don't think it's good the say openly that you're only using the military for the training. On the other hand, if all you want to do is learn to fly in order to do something else outside, take out a student loan and go to Embry-Riddle, Flightsafety Academy, or something. It'll be cheaper in the long run, with a lot lower chance of the dreaded "cap in da ass."
Phrogs phorever