Hello, I am happy to answer your questions. Please see below!
1. Your GMAT is excellent and it does make up for a “not so stellar” GPA. If you want, you may still want to illustrate to the schools that you have the academic ability to succeed in the classroom, by showcasing your quant ability in your resume, your recommenders could do the same in their recommendations, or you could even take a supplemental course such as stats or calculus.
2. Even without direct reportees, you can certainly showcase leadership by discussing the times you have taken the initiative on projects and when you have made an impact on them. You can also discuss when you have trained or mentored others.
3. You will not be at a disadvantage having applied before, as long as you illustrate how your application has improved. That will be crucial.
4. You have chosen the top schools in the world, and while you do have a chance at some of these schools, they are extremely competitive, and each school simply does not have the room to admit all the world's qualified applicants. For that reason, I suggest apply to several schools, including reach, target and safety.
5. You can improve your profile by having specific and realistic goals, and making it clear why you need an MBA, and why you need one from each specific school. Additionally, make sure that you have demonstrated leadership at work and outside of work, to show you are capable of being a leader. You will need strong recommendations supporting this as well.
Good luck!