Honestly, you seem to have everything under control. Your EC, grades, and scores are excellent. Perhaps the Sat could be raised on last time simply because you are applying to such selective schools but its still pretty good where it is now. Just make sure to carry this through your senior year. Chance me for mount holyoke?
I don't know much about Mt. Holyoke, but your academics seem to be in range. The only concern I would have for you is your lack of ECs. Your trip to China seems very interesting; maybe you could write an essay about that?