Enlisting
Take this for what it is worth. I am not enlisted in any branch of the military, but I have jumped through the hoops to try and enlist.
While I was not entering the Air Force, I believe the same applies to any branch of the military. Unless it is on paper, it dosen't mean squat.
I was promised so much stuff when I signed my contract for the USMC. I was promised that I would not be deployed as long as I was in school, I was promised a slot in Officer school, I was promised bonuses, and choice of jobs (which was based on your ASVAB score). Among many of these things, none of them ever came to fruition on paper.
A side note on MEPS. When you go through the whole bunch of tests and exams, you are just a number. The people there don't care what was promised to you by your recruiter. When it comes time for you to sign on the line, unless you actually have enough time to read your contract, if what your recruiter promised you isn't listed, you are not going to get it.
Other than that, the recruiters are just salesmen. Don't get me wrong, serving in the military is not a bad thing, I almost did it. After a good family friend took a look at my contract he showed me where the things my recruiter promised me should appear, and nothing was there. I got shafted.
One of my good friends though just got out of the US Coast Guard, and while he enjoyed it, he is glad to be out. He is though, happy that Uncle Sam will be helping pay for his schooling.
As to your question: do good on your ASVAB, and depending on what is available you might just get a job in the field that you want. Take a good look though online at the required things you have to do if you are enlisted versus Officer. Many times, in the enlisted tours, after you reach a certain rank you must be either a drill sergeant, or a recruiter. And if you actually graduate with your degree before entering the military, you should be eligible to go to Officer school, and guaranteed a commission because you have a degree.
Best of luck
-Scott