Re: stuck on 1 girl and a situation that doesn't allow to sarge any others!
Your concerns are valid. Even if you didn't risk the sexual harassment complaint, it's still a small group of people you have to interact with for more months and would be very uncomfortable if you did something embarassing. (This is how it was back in the tribal times because of small groups) Your best bet is to just test the waters and tease her alittle bit. See how she responds and go from there. You can even use the army as a "forbidden fruit" element that could increase the attraction between you two. One of those "We shouldn't be doing this" kind of thing.
I wouldn't worry about trying to "script" anything beforehand. The problem with scripts is that you can't account for all variables and if things don't go according to the script then you could get shaken. So simply test the waters.
"All things are subject to interpretation. Whichever interpretation prevails at a given time is a function of power and not truth."