It is more an issue of when to level up the wanted great Buildings to some level rather how high.
Early on Statue of Zeus to ten for all players.
Do not level up Oracle at all. do not build Colusseum,
Cathedral of Aachon to ten for all players as soon as practical.
CF depends if you like Quests.. If so build and use early,, up to ten.
Arc. the most important single building. You should have Zeus, CoA and CDM up to tenbefore building this maonster. getting Arc to 80 is the main need of all players. (except the crazies who never build it) it will take months... months. and your Foe life will foreve be better after arcis up to 80.
That is a starter list. plenty of other info to work on too.