Your GPA is solid and your background/experiences are likely fine. It will boil down to your MCAT score, how well you write your applications/CASPER, and luck. For the most part, I believe that college courses are not used in GPA calculation but I would double check specifically with the schools you are applying to. Schools that have a holistic view of your academics may not formally use your college GPA in their assessment but will likely look for trends (aka you'd still want those grades to be solid). Writing just the CARs section is not completely unreasonable, but essentially means you will only be competitive for Mac, and only with a high CARs score.
If you are just planning to write CARs and only apply to Mac make sure you devote all of your energy to having a high CARs/CaSPER score. Otherwise, MCAT will be king and make sure you focus on being a great RN (you'll want reference letters) and staying involved in some sort of ECs or research to continue developing skills and broadening your experiences.