To accomplish your goals you must accept the trade-offs. In addition, it is important to note that different goals require different trade-offs. Again I'm not advocating that you become a sociopath. What I am saying is that if your goal is to get into medical school and your friend's goal is to be a big-shot Wall Street broker, you must realize that you may have to study when he or she goes partying. For one, because if you always do what he or she does, you may end up being a big-shot Wall Street broker instead of being a doctor.
Different goals require different trade-offs.
First, as I have mentioned the grades you get in premed requirements are very important. For that reason you might want to take them one at a time and do real well on them. In fact I recommend that you do NOT take Orgo and Bio together. It is a lot of work and your GPA is much more important than getting over these classes. In the best case you will be asked why you took a class at a different school during the interview and hopefully you will give a satisfactory explanation.