For resource production,
So if I have a huge planet with zillions of mining facilities (presumably because the planet has lots of minerals) I'd have to keep exporting people from it, or I end up with extremely poor production?

Did I read that right?
If so, could the right hand shoulder of the graph plateau at a higher value (say 100%) so that the planet value doesn't crash so dramatically (the only other option would be for the player to invest significant time in micromanagement - assuing that he even knows how badly production drops off with high population values!).
[edit] - ohh, sorry I was writing this while you were already posting yours, so I hadn't read your response. Makes sense, I'd just suggest the higher final value, ie. 100% instead of 10%... sure things are paved, but there's more people to do the resource aquisition.
[ 19 January 2002: Message edited by: jimbob ]