Have you spoken with an AMEDD recruiter? Here is the link
Army Medicine (AMEDD) | GoArmy.com
Truth in advertising-- I'm an officer but I'm not an Army doctor so I'm not going to be able to answer all your questions.
Medical officers go through a basic course. It is not like basic training, which is what I think you were asking. However, you will be learning some of the same basic skills such as saluting, wear of the uniform, etc. that new Soldiers learn. Many medical officers receive direct commissions vice going through ROTC, West Point, or OCS. Therefore, they don't have an ounce of training. That said, the Army is not trying to turn doctors into infantrymen so the basic course is best described as a "gentlemen's course".
Even though your area sounds more specialized than say a pediatrician, I suspect most of our larger hospitals have your department. So yes, I would expect to serve in various locations. I have friends who are Army doctors and they seemed to move as frequently as the rest of us. However, those doctors who have a very unique specialty are often found at Walter Reed and typically stay put. With respect to a 9-5 schedule, I'm guessing your work schedule in the Army would be similar to that of your civilian counterpart.
I love the lifestyle. Over the last 6 years I have been deployed quite a bit and yes, it was difficult, but I don't have any regrets about spending the last 19+ years on active duty. I suspect you'd find your schedule being very predictable. Many people think we work 7 days a week, which is not true unless we are deployed or out training. Now for a nuclear medicine department, I'm assuming it's staffed 7 days a week and/ or somebody is on call?
I highly recommend contacting an AMEDD recruiter. They'll be able to answer many of your questions.
Lastly, being part middle eastern is not going to be an issue.
Best of luck!