By the looks of it, You seem to have a good chance at both USC and UCI. I know for USC (since I am a transfer student attending) all thats required is English and math requirement done by the spring prior to the fall/new academic year. UCI, there is the whole 60units/IGETC and major prep courses done before attending. For UCI, you don't need all GEs but the more you have, (along with major prep) the more competitive you are.
As for SC, your chances seem pretty good, since kinesiology and bio are in dornsife so the majors aren't competitive. Just keep your GPA high, volunteering is nearly a MUST and just work hard on the personal statement. Your SAT and HS gpa wont count since you have over 30 units by the app deadline.
For the W situation. explain why you had to drop it in the last comments section of the app. As long as you don't drop anything this coming spring, you shouldn't worry to much. Also, if you took the W class over and got a good grade, thats even better!
You seem to be on the right track. Good luck! And I would definitely apply to both this year (but SC is better