So is this where we pipe up if we're interested in helping? It's not GIS, but it's still spatial... count me in.

Before I forget: regarding the models for "urbanized" areas... What about using "tiles?". The best way I can think to describe this is similar to a game of Carcassone, with modular tiles that can be combined in a variety of different iterations. It doesn't have to be random, but it can be. You can have a certain number of "cultural" or architectural styles, each using the same "set" of tiles but with a little aesthetic differentiation. Hovel tiles, farm tiles, a "town center" tile, etc.