I had a cursory look through this chain, so apologies if it's already been brought up or closed down.
Is it possible to make the gateway tech demands more open, instead of specific? I mean instead of you need this, this and this tech, in order to advance to Classical Civilization, could you make the rule "you need x no of era techs" to research Classical Civilization. Letting the player choose which route to go, in order to advance to the next era. Which means you could pick the version of riding beast you wanted f.ex. Or be a thoroughly religious civ.
I'm noticing the AI almost always follow mostly the same route of teching up btw. And they have an odd tendency to research already discovered religions. Which is a waste when they're already fallen behind.
Btw. a way to make the religion techs more useful to research, when you haven't got them first, couldn't you make them prerequisite for the religious buildings that you get from other techs? Right now any religion spreading to my lands is just another temple and sub-buildings waiting to be built. Very powerful stuff in a lot of instances, what with +5 food here and +5 production there, even though none of it is my state religion.