I personally would do whatever it takes to avoid taking these classes at a community college. It's true that some med schools will accept CC courses, but it's also true that *all* of them will take university credit.
As for your working schedule -- if there are no universities or four-year colleges that offer the pre-reqs in the evenings, then you may not have much of a choice, as you said. I would rather quit my job to become a full-time student at a university than keep my job to take the pre-reqs at a CC. If you can't afford to quit this semester, maybe you should wait until the summer to start, which would be a more natural timeframe anyway. If you absolutely can't quit and you still want to take a class right now, perhaps you can find a way to work it into your work day? Maybe you can take a break in the middle of your day to attend class, then come back and make up the time in the afternoon. It won't be easy, but none of these choices really is.
Regarding your bio question -- here is where QofQuimica's oft-used advice might be helpful. Seek out a meeting with an admissions officer at a med school close to you. Bring your transcript and ask what you will need to do to best improve your chances of admission. In this particular case, I would be curious to know whether 10+year-old biology credits transferred from a CC would qualify for the introductory biology requirement. I kind of suspect it wouldn't, but I really have no idea.
On a more practical note, you would absolutely want to re-educate yourself in bio prior to taking the MCAT. A lot has changed in intro bio curricula since you last took it. I would personally find it difficult to get through two semesters' worth of biology without an instructor, so I would definitely re-take it. If you can honestly do it alone, and if the admissions officer says your existing credit is okay, than do that...but be very careful!
