Don't wanna hijack the other post from @wowgetoffyourcellphone but it got the ball rolling. so decided to make a seperate thread instead.
My suggestion something along the lines of:
A:
Make Espionage exclusive to village phase but reduce the cost.
Expand vision to support units of the player you selected to bribe.
B:
Make the amount of times you can Espionage limited to something like 3 times a game.
Expand vision to buildings of the player you selected t