Hello!
In the beginning of college, I was considering becoming a chemistry major, so I completed a year of general chemistry (+lab) and a semester of general chemistry (+lab).
I know many of the formal, "brand name" postbac premed programs say they will consider students who have completed one or two of the prereqs. Is this true in practice?
If this is the case, would I be able to retake them, since I will have completed them several years ago? Or would it make more sense to take more advanced electives during the program?
Since you have done so well in that class, don't retake it! You just need a refresher. For the MCAT, pick up a good review textbook (like Berkley Review) and study it on your own.
In regards to taking advanced electives, once you enroll into the postbac program, an advisor can help you pick out classes that tailors to your needs.
If your GPA is solid and you are motivated and diligent, you could consider enrolling in a 4 year university as a 5th year non-degree seeking student. Take your prerequisites there and then take 3 months off to study for the MCAT.