The one thing I'd get rid of is the annoying way the Foreign Advisor works during trade negotiations. You're not negotiating with the AI, you're playing 20 questions with the FA.
Hmm.. offer 120 gold.. "Oh, I doubt they'd accept...". Okay, 140 gold "We're getting close..." 150? "getting close" 160? "getting close" A HUNDRED AND FLIPPIN' SEVENTY?? "getting close..."

Ackk! 180?, oh that's acceptable. Now we gotta do a binary search between 180 and 170 to get the best deal
This isn't negotiating! We haven't even made an offer to the AI yet! We're "negotiating" with the FA, but not really. The FA KNOWS the threshold, but he plays hard-to-guess. I get the feeling that he's really in the service of the AI. I despise him :vampire:
The true negotiation is between you and Civ3 - how much real time are you willing to waste with a boring and repetitive task in order to maximize your profit? There is no skill involved at all, just a mindless zeroing in on a value that the FA knows all along. And how does he know??.
And, how ridiculous is it that the FA knows things like whether the AI has a positive cash flow? Joan, how about you give me 1 gold per turn for Iron? FA: "Oh, they'd NEVER do that"!! [punch]