It`s not really that big of a deal if you don`t do JROTC, especially if you`re going to do ROTC, because the only TRUE benefit you get from JROTC besides leadership, etc, is advanced rank, but only if you enlist. It really isn`t going to help you that much, in my opinion. My school has JROTC, but I didn`t join it, mostly because I need/would rather take other classes to help me rather than JROTC. Nothing against JROTC, it`s an awesome program, but you act as if it`s going to have an effect on you joining.
Also clearing up some other things, just to be clear:
-Health Care Specialist is an enlisted MOS. ROTC will commission you as an officer, so that`s not an option.
-Yes, I`ve heard of some kids taking JROTC at another school, but don`t know how this works.
-Aside from that, there`s outside youth military programs, but I don`t know if they have one for the Army. I know there`s Civil Air Patrol, Sea Cadets, and Young Marines, so you could join one of those, because it has to do with the military, even if it`s not your branch of choice.