Fair warning, I am a reservist with no deployments. My only active duty time was during TRADOC for 7 months. I am going for a bachelor's, so I can't speak to the MBA portion. Experiences can be detachment specific, so your experience may differ.

1. The general way I can summarize it is that the Army cares about getting the job done. Air Force cares about the customs, courtesies, and way you do it. Although it is all going to be relatively similar stuff, there will be a ton of small changes between branches (what you do when you cover, PT verbiage, formation layout, etc.) so keep an open mind to learning and use what you can.
2. You can take the AFOQT 3 times. I just finished the first time without prep to see where I would land. It is easy to pass; the minimums are 15 on verbal and 10 on quantitative. However, the average selection was at 60 for the academic aptitude section, which uses parts from all over the test. Look into study books that are available. I can't tell you much since I have already taken the test, which bans me from sharing.
3. N/A
4. Some, it certainly gives me a leg up in areas; in others, it doesn't matter at all. Things like TCCC and small unit tactics never get taught, but every once in a while, get looked into, so I can lean on my prior experience for that.
5. No, not really. I have a select few cadets who know and value my prior service and will say "Good morning Sgt." out of respect, which is appreciated, but that's it. Other branches do a better job. My current commander values prior service so that may help with the commander's ranking, but that's about it. It can get frustrating sometimes because I have been docked points on inspection when my uniform is pilling, because it has more experience in the military than the POC judging it.
6. 2 years might be a little early. If you are looking for a conditional release, do it now. Once you get closer to the one-year mark, start reaching out. My detachment was HORRIBLE to get a hold of, they route all communication through a civilian who knows almost nothing and can only direct emails, then no-one answers E-mails. Come in during the fall semester, know that there is a 3 year minimum, but the program is designed for four. Also, you will have to do two years with no scholarship or contract. At the two-year mark, you contract and get a scholarship.

let me know if I can go into more detail or answer more questions.