I interviewed in late October, and was accepted in early December (I'm in-state, URM), and I have to tell you that I felt the same way about my open file interview. I was just so nervous, palm-sweat and all, and my second interview was supposed to be with a community doctor and a 4th year medical student, but the doctor was tied up in traffic (my interview was at 8:30am, and it was pouring rain), so I felt like I connected with the medical student, and that might have helped give me some balance.
If you are nervous about your low MCAT, I highly suggest doing a Master's Program if you don't get in. I'm currently finishing up my Master's in Anatomy and let me tell you, it will help tremendously, everyone that I've talked to at KU told me so.
No matter what, do not give up. I interviewed for the first time at KU back in 2010, got put "on hold" in November 2010 and was then rejected in March 2011. I was upset, but I knew I had to do something. Post-bacs are good, but not a lot of them offer federal aid, because you're not getting a degree, just a certificate, so paying for them are a b%#@%. But a Master's will not only give you the opportunity to take out student loans (I know, it sucks, but hey, in the long run, you will be able to pay it back), but also help you show that, yeah, while your MCAT wasn't in the 99th percentile, you still have what it takes to do the work.
I hope this helps. If anyone has any questions about the application process at KU, the interviews, etc. shoot me a private message.
I second this, to an extent. I would add that going above volunteering and actually shadowing, even medical scribing for a physician, will give you a great standing in the "exposure to the field" department. I don't have a significant research background, so that's not exactly a requirement, but it doesn't hurt, but it also won't put you out of the running if you don't have it. Just FYI.