UPDATE: Considering that the 0AD developers already have many ideas and they only want a limited number of factions per game, I will not create the design documents for some new factions.
I am sure you could find some theory that states any given culture had been in America before Columbus. In the first post of mine for this thread, the Wikipedia link is included that states the theory concerning the Romans.
Pre-Columbian Romans are a group of Romans that theoretically went to America. True, these Romans were not in the same geographical area as the Empire Romans, but this could lead to a another 0AD game that takes place in the Western hemisphere - Romans vs Native Americans.
Okay, the reforestation implementation issue is easy to solve. The women and soldiers are already programmed to make a little farm/food-field. Take that same code and edit it so trees grow. Instead of harvesting food, the people either cut down the trees or do nothing more.
Yeah, good points. Wind could be measured by time. (X units * time * windmills). The windmills could then link to some building to grind substances to generate more food. Yeah, I know the idea sounds bad. I just like to brainstorm to help stimulate ideas. I need to look into modding. Thanks for the idea!