This year the cutoff for NC was 214 according to here:
National Merit Scholarships
so yeah, you'll almost certainly be a semi-finalist. About 94% of semi-finalists become finalists, with the 6% either having abysmal grades, SAT scores, or simply turning in their documents late or incomplete (from what I hear). Don't assume just yet, but most likely you are a finalist with those grades.
The whole point of that was to say that USC loves NMF, so that's just icing on the cake.
This is probably because I never really won any national competitive awards, but that National French Exam 6th/8th place award looks impressive, might be beneficial if you could expand on that somewhere in your application.
Basically, right now your strong points are your SAT, SAT II, and NMF status. Your extracurriculars and awards match up with other applicants, only lacking sports but having that French national award. Right now your grades are the main weakness, being lower than the average (3.7/3.8) UW. (This is without considering school rank, as I don't believe colleges place too much emphasis on that, but that's another debate)
I think that overall you have a good shot, with your NMF (prospectively) tipping the scale in your favor. I don't think you will be a scholarship candidate, but if you get NMF then that would obviously not matter (instant half-tuition). Just make sure you write a stellar essay, and try to emphasize that French award somewhere.
I hope I wasn't being too critical here, but good luck!