I'm not sure if you've taken psych and soc, but those are definitely classes to have. The genetics and endocrinology courses look the most appealing. I'm biased towards evolution because I TA'd it and am doing research in it. But anything really is fine for the third course.
Agreed. Endocrinology and Genetics from your list. I'd also consider sociology, psychology, research methods, A&P, or molecular bio if you haven't taken any of those.
If your sGPA doesn't need any help, Psychology/Sociology would be smart, but I've taken 2 Psychology classes and there is little overlap with what is supposed to be on the new MCAT and it doesn't seem too hard to learn on your own.