It makes me drool on my keyboard, which is both a geeky thing to admit and very bad for the keyboard.
I agree with the request for zoom. I like the hint of the categories displayed and encourage as many as possible. I see one labeled Unhappiness and I wonder if it works to separately display happiness and unhappiness like that.
What does the cross hair do? I can understand selecting a point along the x axis for selection or zoom or whatever, but does selection across the y axis get you?
Is there an events replay? I like going back and learning all the events that happened behind the fog. Why have all the processing go into all those events and interactions if I don't get to enjoy them one way or another? If the graphs and replay were available in game, we could learn the history of civs once we meet them.
A big map with forward and reverse DVR-like controls for a visual replay would further endanger my keyboard.