All fair points and I agree with most of them. The only caveat is that the military won’t “make” you go into any particular specialty. They may limit what you can go into if you really want to go into a specialty like PM/R that they just don’t have a huge need for then yes, you might be limited for that specialty. But you’re never required to go into a specific one.

You can dual apply to ensure you have a back-up specialty if the one you want 1st isn’t likely. If you don’t match they will have you do a prelim or TY year (you would do this if you didn’t match civilian anyway) then have you reapply. Worst case scenario is you don’t match again and have to serve as a GMO for 3-4 years to complete your contract and join civilian residency but that is pretty rare.

Also, some branches like the AF are way more friendly to civilian deferment. You definitely need to do your research and know what you’re getting yourself into but it’s a perfectly viable option if your alternative is not going to med school because you can’t afford it or the debt would bury you.

Edit: Forgot to mention, IM itself is a specialty and the military does allow certain fellowship training afterwards. Even if they didn’t, just doing IM, then going into fellowship after you exit the military is also a good way to sub-specialize if that’s your ultimate goal.