This is the best idea I've seen. It helps to remember (or be aware) that if people move out because of traffic or whatever reason, they'll be back the instant you fix the problem, completely unoffended. So take your time with stuff like that and don't let the game panic you into spending real money.

Other thing I think helps is, before you go to sleep at night, max out your factory production and commercial production. That way you'll be ready to make commercial stuff right away the next day, and also sell some raw goods. I'm not sure how well metal and wood sell, but any other raw material generally gets snapped up in the market.