Hiya, no simple answers. I went back to cc after getting my BS and took allied health classes and spanish. In the mean time I took Ochem and Gchem and an UD Bio Lab as an open campus student (pay full price, but worth the experience and the higher pace/challenge). I have interviews/1acceptance with that history, but did not do any of my pre-reqs at CC. So going back does not count you out, pre-reqs are another story. . . .
In my recent interviews/shadowing I have met several CC students who are now med students and doctors. They did the normal LD at CC and then transfer for upper division at 4-year. That suggests that it will not count you out for going to CC. Yay!
Let's say you execute this plan and rock your CC classes, participate in different campus programs or help start up new projects, leaving a legacy at your campus. There are great opportunities at CC and not as many competitive pre-meds to compete with. Plus your efforts at a CC are often very relevant to the local community, developing your perspective and abilities as an individual heading for a profession that needs more sense of community. Then, you move on to that 4-year that you prefer and continue to rock your classes (cuz you are dedicated and focused and passionate), meeting new professors (for letters of rec and research opportunities) and fighting for access to the abundant shadow and volunteer programs that you expect to find here. By the time you apply you have great recommendations and experiences plus you have accomplished your goal of attending your university of choice. I can't imagine that an admissions member would ignore your successes and decide that switching universities was an issue. If your passion and performance is there, than your early years will be overshadowed.
Reality to keep in mind: A friend has discovered that some universities do not accept CC credits (which I think is BS and basically counts out a huge portion of the population, esp the "desirable" low-income minority). Anyways, she learned this be reading through MSAR school by school. I would take this into account and realize that this choice (like every choice) could exclude you from some schools. This makes sense because you are not meant to fit into every school, you should fit into the ones that reflect your goals/interests/attitudes. If your path takes you to CC then F-the schools that turn their noses to that. I believe that pursuing your goals will always take you to the right place.
Good luck!