This is incredibly impressive, massive kudos to you
I'm not too knowledgeable about the limitations of what is possible with ff7 and the technical side, would you be able to expand the world maps? Would we be able to have a scaled up Gaia?
Is it more for texture replacement potential?
could you potentially have more maps?
The features are very impressive
You cannot make the current maps bigger without modifying the game's engine as it makes a lot of assumptions about the map size. As wdx said you can edit, add, remove places on the current map, with enough patience you could reshape the whole map and add new events on it.
FF7 has three world maps: overworld (id: 0), underwater (id: 2) and great glacier (id: 3). Technically it is possible to tell the game to load an arbitrary map id which would make it possible to create an alternate version of overworld, but you would need to slightly hack the exe to make it possible to enter that map.