Everyday I’m asked by HL LC Maths students “Can I get away with leaving this out?” 

The answer depends on the student and what topics they like, but as a rule of thumb it’s safe to say you could away with not studying one minor topic in each paper. Eg. you could leave out Complex Numbers on P1 and Geometry Theorems on P2. 

I would not recommend leaving out more than one minor topic on each paper because you could end up having to attempt some very difficult questions if you do.

I cover the whole course with my students but I don’t advise them to focus their efforts evenly. Spend more time on the topics you plan to do in the exam! 

Best of luck to all students in the LC and JC in the State Exams!