How would AFJRTOC effect my chances of being accepted to the Air Force Academy or AC?

Well, first consider yourself lucky your school has AFJROTC. The school i go to is too small. Yes, it does help you, but it doesn't give you much more of an edge. But it does prove you are involved in extracurriculars. As for the blood drives, just ask. I wanted to do the same thing this year at my school, but again, we're not that big so only the Advisor runs it really. Good luck though, hope you get in.