GG,
this "fascinating amount of sophistication" has more than once left me wondering if anything in this game was not random...
Let's say sophistication can easily make a complex system seem erratic, even chaotic. Since 1.5 I can't seem to get my diplomats to do me any good whatsoever. And every time I try, they pick up bad traits (not very courteous, or whatsitsname, being a prime suspect) from failing, just because the AI doesn't allow anything it doesn't come up with itself.
The same seems to hold true for governor traits. I usually don't rely on governor training anymore - it's too much micro work and doesn't pay off enough. If I can conquer 40 provinces in 60 turns with only fools for governors, while my generals turn into heroes on the battlefield because I fight so much and so hard, I can skip caring about governors.

I don't want to sound destructive of the fantastic work done by Aesculapius, Sunsmountains and others. I just think that these "soft" parts of the game - governing, diplomacy etc. - could have been made better by streamlining. Where there're so many variables in an equation, it's virtually impossible for a player of the game to actually see results in a simple, yet satisfying cause-and-effect-chain.