With permission, I'll make one more question about growth...
I had no patience to verify it, but when I built the Sacrifice altar (growth penalty), the city (level 2) started to loose population. If population falls to level 1...has someone checked what happens?
You can't loose city levels again (there are certain spells that kills population, and me cheesing the maximum food with city enchants).
So all that happens is its going to take a lot of growth to get your city to level 3.
Sincerely
~ Kongdej