well i have played at most at the monarch level and find it fairly easy to beat up (thanks to the resource shortage stronger AIs suffering
dont think emperor will be (much) more difficult than that.
did not like the idea of softening deity though. i mean the ideal is to make it play smarter but since that is not an option, "making the game harder though giving bonuses to AI" option is not that bad. i mean if it is frustrating you, you can always play at a lower level.
you know, if you were to beat the most challenging oppponents that the game can offer in a couple of weeks and no multiplayer around, what would you do next?
so my bet is to leave it as is.