I added a rules change in the second post, since I didn't want to upload another PDF of the rules. Stability now determines base population growth, with growth peaking at Stressed and falling off slowly above it and rapidly below.
Secondly, before the game begins, players need to spend their IP or it will all be banked. With that said, I'm going to warn players before the game starts if their builds have any issues, such as a shortage of raw materials. You'll have the choice of accepting the build anyway, or rebalancing it.