Well I'm assuming you were employed full time during these gaps no? And did some clinical work consistently throughout? I don't think you have to worry too much. Just have a good story and narrative of why you want to do medicine now and you'll be ok; 3-4 gap years isn't even that unsual these days. Continue to collect clinical experience.
You have amazing stats, good clinical experience, good non-clinical volunteering, good research experience. I think you'll be fine and can honestly aim a little higher.
Consider adding to your current list: Einstein, Hofstra, Jefferson, NYU, Sinai, Cornell, Columbia, Pitt, Ohio State, Emory, MCW, Cincinnati, Wake Forest, Miami, Tufts, Boston U.
I don't think you need DO schools.