game based discussion boards

These already exist, every store page has a “Forum discussion” link. You can also go here and you should find the “game specific forum” section where you can search for whatever game.

It always bothers me that red houses only ever want to go to red buildings and that you can just leave a lot of the houses completely unconnected to the road system you built. But making a slightly more realistic traffic simulator would probably be a lot more complicated and a lot less fun.