I think this is a great idea and though I would love to help, I can't do anything more than make suggestions as a casual CIV player and modder.
The main thing should be that there aren't limits on the game, like limited numbers of units, buildings, civs, cities, whatever. You want to leave everything open so you can add more later. Like if you can't decide whether to put Canada or Australia into your modern scenario, you can do both because there's no limit on civs.
I think an effort should be made to make each civilization very unique; for example flavor units and buildings. So probably at the beginning there will be very few civs, but room for alot of expansion later.
Also the addition of canals into the game would be a great concept. The ability to build the Suez Canal without destroying Alexandria and Cairo's production would be nice, and this also ties in to the desire to rework production and population.
I also think there should be a way for civilizations to import more things, not just resources, like the United States exporting old F-4 Phantoms all over the world. This would add to the ability of a less advanced civ or one which is resourceless to compete in the modern world.
The main thing should be that there aren't limits on the game, like limited numbers of units, buildings, civs, cities, whatever. You want to leave everything open so you can add more later. Like if you can't decide whether to put Canada or Australia into your modern scenario, you can do both because there's no limit on civs.
I think an effort should be made to make each civilization very unique; for example flavor units and buildings. So probably at the beginning there will be very few civs, but room for alot of expansion later.
Also the addition of canals into the game would be a great concept. The ability to build the Suez Canal without destroying Alexandria and Cairo's production would be nice, and this also ties in to the desire to rework production and population.
I also think there should be a way for civilizations to import more things, not just resources, like the United States exporting old F-4 Phantoms all over the world. This would add to the ability of a less advanced civ or one which is resourceless to compete in the modern world.