Only if your IGCSEs don't overlap. If you're starting sixth form in september and taking your IGCSEs in november 2 months later then no, you can't. If they don't overlap, then yeah, you just apply with predicted grades.
You'll then call up on results day and explain what grades you actually got, and if you still have a place.
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.