With Warlord release and patch 2.08 we got a lot of balancement changes which nearly resolved all issues in the game.
If you think that there are features which are not yet balanced and needs to be resolved list it here.

These are mine:

-An algorhytm which makes religion spreading different based on how religions are on the tech tree.So Buddhism and Induism get the lower spreading rate, Hebraism a bit more faster than the first 2 religion, and the later religions with higher spreading rate particularly Islamism.Otherwise it could be resolved by giving later religions some free missionaries.

-Barbarians should use Spearman so Chariot aren't overpowered against them

-Barbarians should use Galleys and Triremes marauding your water