MG, I was a T-1 flight commander in my previous AD life, so I can answer no to your first question, "sort of" on the second. The "needs of the Air Force" certainly prevail in what we call the "drop". A few weeks before graduation a list will appear that contains a number of airplanes equal to the number of graduates. Right now, the AF needs more C-17 pilots, so there are large numbers of them on every drop, along with assorted KC-10's, KC-135's, C-130's, C-5's, C-21's, etc. Additionally, there are usually 1-2 opportunities to stay on at the UPT base as an instructor in a T-1, or occasionally a T-37 (or for you class, a T-6). When the Air Force decides it has enough C-17 pilots, the focus will shift to their next hot item, and you have zero say in that matter - as I said, the needs of the Air Force dictate the list. However, it is your performance that dictates which plane on the list you get to fly. With few exceptions, the number one pilot gets his/her first choice. The number two pilot guy gets his first choice unless the number one guy took it, then he gets his second pick, and so on...
This a grossly oversimplified view of the process, but about the 90% solution. If you have more specific questions, PM me. Congratulations on the selection, enjoy the summer weather in Montgomery (at least you're in God's country)!
Bamaboy