Itemize your 500+ hours of non-clinical volunteering, and break out the hours that you are claiming as "leadership" compared to direct interaction and involvement with other community members (not your student peers or other members of clubs you are involved in).
On your original question about your CARS score... I presume with your GPA you've had a fair number of reading-intensive courses? What did you take (because you got A's in those classes) and how much reading was involved?
Are you a first-generation student growing up in a non-native English speaking household?
Why are you "brand school" material? With your posters and thesis accomplishments, and you'll likely be PBK, why don't you pursue a PhD?
What is your state of legal residence?