Been a way for a while, playing Stellaris a lot and just recently popped back onto CivIV for a spell. Udpated the game and started playing... A few little things I wanted to throw out here:
One, is the "Assimiliation bug" I brought up a whiles back still seems to be present. Here's what happens:
Portugal settled a city a few tiles from one of my border cities. I got an event later on that spawned five barbarian archers and instead of attacking me they marched south and attacked his lightly garrisoned city and captured it. The city rightfully had (Portugal) after the city's name, signifying it once belonged to their nation. I gathered up some units and captured it for myself, and the (Portugal) suffix disappeared. As far as the game is concerned, it was never a Portugese city - it's always been a Phoenician city
(playing with the civ megapack here, but it happens with standard nations too). Whenever cities trade hands between nations, the original owner's nation is always labeled. Whenever the Barbarians take a city from a nation, and then another nation takes that city, the original owner's nationality is disregarded.
Second, is the AI are still very too much focused on valuing the manufactured resources when offering trades. That is, currently in this same game, I've removed Portgual from my island and forced Sitting Bull into playing a OCC game in the icy wastes along the rim of it. I have contact with five AI from the mainland currently. After a while Persia pops in and proposes an Alcohol for Cows trade. I don't particularly like it, but I take it anyway as it saves me the trouble of building a Brewery myself and I have an abundance of cows. Two turns after this deal expires, another AI proposes the same trade. I shoot it down. The very next turn I get two AI both asking for some resource in exchange for - wait for it - Alcohol. I tell them both to shove off. Turns pass, and then an AI comes in asking for Cows and 5gpt for..... Alcohol. I tell him to get lost and then a few turns later one of the AI repeats the same "X resource for Alcohol" trade I declined ten turns prior. This goes on and on until I build a Glassmith, after which a few of the AI start asking about Glassware for Alcohol - with of course the same Cow/Copper/Marble/Potatoes for Alcohol trade offers mixed in.
I figure this is because in these cases Alcohol is a resource I "don't have" and so to them it must be a good deal, but you can make Alcohol yourself - it's not like being starved of Fish, Copper, Corn, Gems, whatever... It's just a matter of building that structure yourself. Usually once I build one of my own, every AI ceases using Alcohol in their offers. Right now I just accepted an Alcohol for Glassware trade with a nation since I'm trying to get him to open his borders to me - and as with before, all the AI immediately stopped proposing X for Alcohol trades once this deal went into effect. I don't see them get this excited when I'm lacking Pigs, Spices, Corn or Bananas, but if I don't have Alcohol or Paper they go absolutely nuts
And about that... Once Paper Mills start popping up, the AI is VERY insistent with pushing their "X Resource for Paper" offers.