I think that with the question from 2009-2011 this was needed, but since they changed back to the pre-2009 format - you were meant to focus entirely on the person. However, adding a couple of paragraphs in relating to the other aspects can't hurt, although i didn't choose too since the question...
I didn't, the question clearly asked for person. In other questions they are a bit more broad, allowing you to use all 3 parts - but in this question it didn't
One a about how effective the responses to challenges of megacities, and the other was the environmental, social, and economic impacts of a global economic activity. (Don't remember other one)
yeah i thought that, but size the size of population has no effect on whether it is a world city or not. its about there economic, cultural, political power etc.