I am interested in #4 above as well...
also, to add to this: my recruiters told me I would lose ALL VA benefits and had to sign a form with the VA to decline any future benefits until I am done many years from now with Army Med. This is absolutely not true and was particularly important for me for medical coverage (Afghan vet less than 5 years out). So you get to keep all of your current VA benefits. The only catch is that when you go AD for your ADTs, you have to submit a form to the VA detailing the days that you will be AD so that they can immediately stop pay for that time period (the 45 days per year) and then obviously you submit forms when you graduate and recommission. So pending an awesome answer on question 4 above, I will get: HPSP stipend, plus 9/11 stipend, plus VA money from when the Army broke me, plus VA healthcare, and I will lose all of those for the 45 days a year I am AD during med school.