First, I disagree that JAG is like a clover of garlic to the vampire that is BigLaw. I think it is an excellent springboard to litigation work. Being thrown to the trial court wolves (I'm having a weird metaphor day, forgive me) early on as a JAG gives you an incredible amount of experience, much more so than any junior biglaw associate would gain. While going to trial is being less and less common, the fundamental skills translate easily all the ADR options. Further, as soon as you are commissioned, you are actively practicing law as a JAG. Though you are working in a variety of fields, you are not doing document review or merely writing memos. I would think that while you are less specialized after 4 years in JAG, you are a more effective practitioner when compared to 4 years of BigLaw.
I had the opportunity to spend time with Gary Shapiro, the First Assistant US Attorney for the NDIL, over my christmas break. AUSAs are rarely hired straight out of law school and he said that JAG tends to be one of their biggest recruitment pools, trial experience being one of the primary reasons. So, while AUSA is not BigLaw, it's still PrestigiousLaw, and OptionsAfterJAGLaw.
If you are hoping for corporate transactional work, I will readily concede that JAG might not be the best idea in the world. However, as a Chicago boy, I've been eying Boeing's in-house counsel office as a possibility. Nothing to back this up with. I just figure AF has airlines, Boeing makes airplanes, and knowing what I know of DoD staffers lateraling into defense contracting firms, might be a possible lateral option.
Second, to the OP, you seem to have this pretty well figured out. I love the flow chart (I laughed my ass off, bringing glares from my law library table mates) and you know the pros and cons of the decision. Some people looking at JAG seem to be inspired by Lt. Kaffe/Capt. Harman Rab or are in the bottom of their class and figure the military will be an easy employment option. I'd suggest, barring your Wisco admit, to rock out St. Thomas if you are truly concerned about the debt issue. Worrying about future injuries is just absurd. You may get hit by a bus tomorrow as well but I doubt that is guiding your decision with all of this.
Speaking to the debt issue, I'm at Illinois with no scholarship (though in-state) and will come out about $80K in the hole. Having worked out projected expenses, projected income, etc, your/my 0-2/0-3 salary can accommodate loan repayments with a solid standard of living. It will be much easier coming out with no debt, but it is also totally do-able to go T1.
Additionally, I would think that if you wanted JAG -> BigLaw, having T1 credentials would make that far easier.