Lots of stuff may or may not change between now and when you would actually go through residency and whatnot. That said, here are a few attempts at answers:
1. Chance of being a GMO is going to vary a lot depending on the service. It’s highest in the Navy. At least in the Navy doing IM or Family is not a protection against going out to do a GMO tour. The number of people they are taking straight from intern year will vary year to year and by specialty and service.
2. Civilian deferments are the exception not the rule. If you do HPSP or USUHS, assume you will do your training in the military GME. (Barring large changes to the way milmed is set up)
3. Deploying and “going abroad” are two very different things. I’m assuming you mean you want to be stationed overseas somewhere like the PacRim or Europe? People generally do not do back to back OCONUS tours as detailing guidelines I believe don’t allow it but they do sometimes make exceptions. Some people wind up getting more overseas orders than others and if you aren’t picky you could probably wind up OCONUS a few times in your career if that’s what you want. You won’t spend your entire time OCONUS though and if you only do a single or two duty stations (your minimum commitment) there is no garuntee that you would be able to get overseas. (You generally have less input on where you get to go early in your career)
