Your priorities
1) Doing something you enjoy and living a life in a place and under circumstances which you can thrive in and enjoy during this time you have off
2) Getting the best MCAT score possible
3) Getting clinical exposure and volunteering experience.
And at a somewhat distance fourth
4) Adding more EC's for your resume
You essentially have 8-9 months to prep for your MCAT. The best bet is to try and give yourself enough time to study for a re-take if it comes to that. You already have research experience. You don't really have clinical experience beyond shadowing. Many people get into medical school with your kind of research experience. Far fewer get in without real clinical exposure beyond shadowing.
Bottom line prioritize here. Come up with a plan for how you want to spend these next 9 months. When do you want to have that first MCAT attempt in by which would give you enough time to study for a re-take if you need to retake. February? March? You gotta decide that and build your schedule around the MCAT. Figure out when you want to study for it and whether you can do other activities on the side like volunteering while you study or work(best bet here is to be conservative and try to do the bare basics outside of studying during that time). From there you can build around the rest of your plans. You need to get more clinical exposure. You really want to beef up the volunteering. Volunteering with the less fortunate, disabled and terminally ill would be very beneficial for your app(think hospice work or something). A job in a hospital like a nursing assistant where you really serve for others and get great clinical exposure would help you alot as well. Research is all well and good if you are very passionate about it, but you gotta ask yourself how passionate you are about your research and how much of a commitment you want to make to it. Doing full time research while also studying for the MCAT is difficult and often not a great strategy. Doing full time research, beefing up the clinical exposure AND studying for the MCAT is going to be asking for a ton and isn't the most realistic for many. Even if you can pull it off it will require alot of sacrifice on your part.
So that's how you gotta look at it. Whatever you do, you need a plan for these next 8-9 months.