APs are nice, so are IBs, they're great for getting a bunch of credits, especially in less than useful things like Gen EDs or Electives, you pay that much less. Sometimes you can even become a sophomore via credits (although it may not be suggested).
As for myself, I've already taken AP Calculus BC (kinda hard, but I feel like I got a 4 or 5). Then a bunch of IBs and more to come. Then 3 late APs (Computer Science, US History, English Lang) on the 19th and 20th.
Also, don't worry too much on the Physics B. Basically, there is so much content that everyone is extremely unprepared. Getting half of the MC at best and 1/3rd of the Free Response netted me a 3 (my worst AP, QQ). Basically, if you can get like 60-70% MC and 1/2 to 2/3rds of free response, that's a 5.