Hello,
I wouldn't panic yet about the scores for your SAT II's, the Math as long as you got a 5 on the Calc BC exam is pretty easy, and all that I have met that have taken Calc and at least passed have done really well on the exam. A lot and a lot of people got 780-800 on the exam. There is NO calculus on the exam, so if you haven't taken it don't worry about that. It is good to study for it if you aren't up on your math. As far as importance of the SAT II's well most universities tend to holistically look at their applicant, so as long as your EC's and grades are good you'd be ok. If you want to be "chanced" for your respective schools, I've included a great website in the source that you can browse that will provide you with a plethora of information on applying to college. I spent countless numbers of hours there last year when I was applying. Don't let their super stats discourage you though! Anyway, good luck.