strange. in my current game the celts and byzantium declared war on me long before that. And i need units to fight them of. the reason they declared war was a lack of units on my part because of the suggested gameplay in this thread.
again . . . wishfull thinking. it might happen that you can fight them of with diplo or otherwise, but it probably will not.
Perfect stats perfect scenarios and all that.
I keep saying this but you can cook any number of situations in Civ5 that will make an immortal game feel like Prince.
Having that one agressive Civ closeby and no one else to absorb their anger is always a possibility and could make an Emperor game feel particularly hard if a certian mix of Civs screws with your plans.
Winning by X turns is always an interesting exercise in optimization, but if you play with random Civs on non cooked starts, it's always aspirational. It's just as fun to ovecome the challenges presented by the map/CivMix