I'm most familiar with Urban Fantasy romance novels (esp. Kresley Cole and Larissa Ione) where the POV alternates between Him and Her.
1. From the perspective of those who write these kinds of stories, who is considered the Main Character.
Both? The person with the most connections? Always Him? Always Her?
2. Queries tend to start: Main Character wants nothing more than to be something. If there are two MCs do you tend to choose one depending on the agent/agency or would the query look more like the blurb on the back of the book? "She needs X, He needs Y. Can they overcome their differences to Z?"