Congrats on your great scores, and bringing up your grades. With any luck, USC will consider that your lowest grades are in art and PE classes - maybe that's something you can have your counselor discuss in her letter, especially if you have a legitimate excuse (i.e. not just that you blew off the class and made the teacher angry
It would also help if you could get the counselor to address those low grades in the school recommendation that you'll have to submit to NM to be considered as a finalist. I've observed on CC that kids with a 3.3 can definitely make finalist, but some have reported not making it because of C's or D's on the transcript.
That said, making NMF would be great for your chances at USC. Be sure to request an interview, and don't limit yourself to the one teacher's recommendation that USC asks for (or at least used to ask for). And prepare yourself for the possibility of spring admission - your grades might put you on the bubble for fall admission, so don't be surprised by that.