Yeah Lee, I definitely have to agree with WaterBomb here. When I act that way with a guy, confiding in him like THAT ("sigh i just worry that i'll never meet a guy that i can fully trust and be myself around"), I am totally head over heels for him. She is totally dropping hints-- no way she isn't interested.
And as for the not being able to handle a relationship at this stage in your life... well... I think that if you two get along that well and respect each other that much, it could actually end up working out if you give it an honest try. Especially since she already knows you may be joining the army and she DEFINITELY knows you're 100 miles away from her, but she's still interested. You're already great friends, and you've been able to keep that up despite the distance, so taking it to the next level doesn't seem completely nuts.
However, if you really really really think you can't handle a relationship now and she does end up coming on to you directly, be honest and don't pussy out of it. Tell her how you really feel-- how it's the distance and the army thing that are getting in the way, and that maybe someday something could happen because you do have feelings for her, but it's not a good idea right now.
Personally, I think you should make a move now while you're still at the top of her list in terms of guys she's interested in. If you don't, someone else will, and you may end up regretting throwing away your chance when you had it.
Edit: well if you don't like her "that way", be straightforward about it if she asks. Just make sure you know your real reasons for saying no-- is it because you don't like *her* that way, or because you don't want to be in a relationship? These are two very different things! Also, I don't think either of these really qualifies as "friendzoning" as long as you're honest about your intentions
