you're only gonna take the sats once more next year, even though you have the whole entire year and usually u do better on sats as you advance through school?
Anyways, i took the Sat2 math2c twice just ending precalc and i got 740 both times, its damn tough though. Buy a book to study from, although there only a few calc concepts like limit and easy stuff, your gonna need a book. taking the 2c also depends on what schools yoru gonna apply to: i guarantee you all Ivy leagues want their students to take the sat2 2c. Most reputable private schools also reccomend you take them. The thing about the 2cs though is that they make it so you can miss up to 4-5 questions and still get a 800, but its still really though because of difficulty and time constraints.
you want to ask yourself: are my math2c and 1c scores goning to be that different that i shouldnt take the 2c? What did you get on math on the sat1, that is somewhat a determinant of which one u should take.
about that physics score: not to be judgemental or anything, but thats not a great score if you plan to apply to high powered schools. The bio,physics,history, chem tests are usually designed to be taken after the respective AP course in order to achieve a higher score. Wait until the end of next year after you have taken some more AP courses and take that courses' SAT2 subject. Also, Usually high powered colleges like to see nothing in the sat2 lower than a 700.
About the writing score: i know friends that started out with 500 and were able to work their way up to 700's. Dont worry, but for writing, unless your read tons and know lots of grammar, you gotta study for it. I started out with a 640 and bumped it up to a 730 i believe. Plus the writing test is good to take numerous times because alot of it depends on your essay, and sometimes you might get a topic that you like and often times you will get a topic that you hate. Take the writing test at leat 2x...
which colleges are you thinking about btw?