As far as medical, I really don't know the yr that asthma becomes a player. I want to say it is 13, best to ask that over on the DoDMERB threads. It really is a case by case, and many times they will ask for a remedial first to see if it was a mis-diagnosis.
Regarding broken bones, etc., I wouldn't worry unless a surgery was required, and even than again they may just request a remedial first.
Sometimes they just ask for the paperwork. The reason I said get the paperwork in order is because people tend to overlook that part of the process. The problem is if a waiver is needed it can take as little as 2 weeks and as long as a few months.
As I said you can be in ROTC, but the scholarship won't activate until you contract, and colleges can "lock out" a cadet from registering the following semester if the 1st semester is not paid yet. For all 3 of my kids registration started in October/Nov. depending when they started in the fall.
Additionally, nor will you get the book allowance or stipend.
Personally, I would just get all of it together, because either way he will be leaving the nest eventually. We took a CD-ROM to the docs and had them download it, so he could take it with him to school and had access to his records in a moments notice if something happened at school.
One thing to understand about the AF is if the major is considered a critical manning field, than going to UPT/UNT/RPA/ABM is off. I don't know if Russian is considered one of these majors, so I would suggest he checks with AFROTC to see. I think AROTC does have a better program than AFROTC when it comes to this aspect.
I also would point out that if I am correct there is a huge difference from a commitment payback. I believe the Army is only 6 yrs from winging as a pilot. The AF owes 11 yrs, and to wing it takes one yr. In essence, 12 yrs., and if they go casual status, it could be 13 yrs. DS is at UPT now, and will not start class until Apr. That means he can't leave until April 2025 as a 12 grad. Your child could be 2030.
He needs to think about that too.
Also for AFROTC you apply for the rated board, but you have to be willing to take any of the career paths, such as CSO/Nav, RPA (UAVs), and ABMS. There is no guarantee that they will get pilot. OBTW the time commitments for them are not 11 yrs., it is 6 (I think). For our DS graduation class last yr., 13 asked for rated. 13 got rated. 11 got pilot, 1 got CSO (eyes), 1 got RPA. Chances are statistically pretty good, but who knows what it will be like regarding slots available in 2016 when they go up for the board.
The scholarship is just the gravy. You have to want this life and be willing to serve in any career field for many yrs. Don't go one path because of a scholarship, go because you want to wear that uniform.