Not really...haha it matters how well you do on your SATs and essays too. Ivy Leagues won't look at individual courses but rather your GPA. So as long as your GPA is about 3.8 or higher your're fine!
Don't worry about the Calc AB/BC thing. My high school's valedictorian is at Harvard right now and she only took AB, even though we offer BC too.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.