Has anyone else looked at the map of Paragon City and wondering 'what if they expanded the zones?'
If you look around their zones, you can see lots of space not 'protected' by the walls, so theoretically, each zone could be expanded and new zones added on in the outskirts.
For example, Steel Canyon has some pink areas to the top, lower left, and lower right you could add in to the zone. Atlas Park has some green you could expand into; Galaxy City has a little green to expand; Brickstown can be expanded into the brown area around it. The green peninsula, brown and green left of Steel Canyon, and gray at the top middle, all could be new zones to explore. Imagine the gray being a 'rich people zone' with historic houses (imagine Savannah, GA, or Riverside/Avondale in Jacksonville, FL style houses), with beaches, docks, marinas, yachts, and cruise ship missions. Siren's Call being expanded to the entire purple area. Galaxy City and Atlas Park both growing in size. More missions and new places to explore.