I've dealt with similar things, and learned to focus on what I can instead of can't control. For instance, I received a C in an upper division science class due to a poor TA, couldn't prepare for the VR portion of the MCAT since I had to deal with an unexpected situation, etc. Instead of dwelling, I did things to improve my CV in ways that would address the above (e.g. took the GRE and received a good verbal score, earned A's in harder classes within similar subjects) while pursuing my interests. Bad people, difficult situations, etc are part of life, but how you handle them when they present themselves and what you do afterward are more important than worrying about the areas you mentioned.
So, my advice would be to study for the MCAT next time if you'll retake it and more or less learn perspective. As far as target schools, find a match with your research interests outside of the really competitive ones and tailor your research/ECs to those. Your future PI will care more about your ability to be a productive, interested researcher than the areas you're concerned about, while medical school admissions committees see things in more black and white; the post-baccalaureate forum is useful for the latter, although I think there are better options than SMPs in your case.