Some thoughts since you have time before you go. Most importantly you are apparently smart having qualified for a Nuc school. That leaves us to ponder some of what you post...
Don't screw up the smartness. Nuc schools have a lot of washouts and I think most of them are not directly related to the schoolwork. I talked to/mentored a ton of nuc wash-outs and they were all quite smart, most failed at school because they weren't studying and taking it seriously. The school barracks life is unreal, you have money, what feels like absolute freedom after boot camp and parents, and plenty of distractions like buying expensive crap you don't need, girls, PS3, and alcohol. You screw up nuc school and you are taking yourself out of the running for your enlistment bonus, large re-enlistment bonuses, good advancement, and cake civilian jobs. In short over the years you are potentially paying 7 figures to be stupid and not take nuc school seriously. Some of the drop-outs work back to a good rating, had a few as ATs in the aviation world. They still cost themselves and they know it. So even if you hate the military, smile and say yes sir, do your job well and hit the door when your time is up with your enlistment bonus and your college benefits intact. Any other way out is the wrong way.
A word about college benefits. They are going to start paying full tuition, give you $1K/year for books and pay you a monthly tax free housing allowance for 36 months to go to college. That is ridiculous money, ask anyone on here that has student loans. Don't screw it up by getting kicked out.
A word on smarts. I cut a 99 on the ASVAB, was hounded to go Nuc, finally took their little test to shut them up, got 70/80 right they were thrilled, asked me again to go nuc and I declined. They were not thrilled. Smart only gets you so much. The rest is doing your job, getting all your qualifications and being a leader whenever you can. I made first class(E-6) in 5 years. I quit active this year after 14 years, still a reserve 1st class. I can cut 80s (max score) on the chief's exam, done it four times actually. I had to basically suffer 5 years not getting promoted for not being able to run 1.5 miles back in 2002. I'm not sorry, I'm a pretty good first class, had a chance to warp lots of young minds. I would have never made 1st in 5 just on smart, I was a minor god at my job and I did what I was told.
Good luck to you, don't screw this up!