The technology disparity is crazy. Even if you told me this was on Deity, I could believe it. The AI seems terrible mid and late game.

As for the graphic problem, two questions. One, is this the ludicrous size True Earth map? Two, how long was it running at this point?

There sre two things that I found help (though I haven't encountered this specific problem). One, switch between the tactical and regular map. For whatever reason it can smooth things out for a little while. Second, the tried and true turn it off and on again.