All right, let's see if I can remember all the changes I made:
-Added the
Expanded Great People mod (though I removed the Medic unit, as it's more designed for modern eras).
-Leader traits seem a bit unbalanced. I made Agriculture receive its bonus on all plots with 4 food instead of 5, to match the Financial and Productive traits. I plan on making further changes however, as every Civ with either Expert or Aggressive seems significantly more powerful than the others. Playing as the Romans, the top civs are always the Germans, Tartessians, Persians, and Egyptians; the Goths are always wiped out early, the Gauls are easily annihilated by the Germans, the Greeks never really get anywhere, and the Carthaginians lag far behind without my aid.
-Open Borders now available with Writing tech (instead of Exploration tech). Open Borders took way to long to get in the default game, and I always found myself completely boxed in by other civs until I discovered Exploration.
-Vassal States now available with Empire tech (vassals weren't available in TAM previously).
-AI attitude thresholds made more lenient. Previously in order to get a simple Open Borders agreement, you either had to gift several technologies to a country or be at war with their enemy. This is what I changed the attitude thresholds to:
~~Cautious: Unlocks Open Borders, Tech Trading, Map Trading, and Health/Happiness Resource Trading for most leaders.
~~Pleased: Unlocks Religious Conversion, Civic Adoption, and Strategic Resource Trading for most leaders.
~~Friendly: Unlocks Vassalage, Defensive Pack, and Permanent Alliance for most leaders.
-Philosophy tech now gives +1 happiness, instead of giving a free tech to the first one to research it. I did this because Philosophy previously only gave benefits to the first one to reach it: they received the Zoroastrian religion and a free tech. So, now other countries get a benefit from it, instead of just the first. Not to mention happiness was rather lacking in the early part of the game.
-Holy Book tech gives +1 happiness to all who research it, in addition to giving the free Great Prophet to the first to reach it. Same reasoning as the Philosophy tech change: to give some benefit to all who research it, instead of just the first one.
-Aristocracy tech gives a free Great Statesman (from Expanded Great People mod) to the first to research it.
-Education tech gives a free Great Citizen (from Expanded Great People mod) to the first to research it.
-Medicine tech gives a free Great Doctor (from Expanded Great People mod) to the first to research it.
-Changed most of the buildings to have a 66% chance of surviving a city conquest, instead of 0%. All World Wonders also now have a 100% chance of surviving conquest, instead of 50%. The only buildings with a 0% chance of surviving are cultural/scientific buildings (obelisks, libraries, amphitheaters, etc.) and military buildings (walls, barracks, etc.). I made this change because I generally focus on conquest in my games. However, with so many buildings being destroyed when I took cities, it seemed like there was too little reward for military victory. I eventually started just razing everything I captured, since it'd be easier than having to deal with the angry locals. With more buildings surviving conquest however, there should be more incentive to keep cities instead of razing them.
-Academy gives +25% science, but requires at least 4 Libraries to build. Observatory gives +25% science, no longer gives +2 culture, requires at least 2 Academies to build. The idea behind this is to allow cities to specialize, as each civ would only be able to have 1 or 2 Observatories. A similar approach could be taken for Wealth buildings.
-Instead of giving +1 happiness, I made Amphitheaters give +1 happiness per 10% culture rate. This is to not only make the culture slider more valuable, but also to make happiness (which is vary scarce in TAM) more available.
-Public Court gives +2 espionage.
-Courthouse additionally gives +4 espionage and +1 happiness per 10% espionage rate. This was an attempt to make the espionage slider (which generally seems quite useless to me) more valuable, but I haven't tested how well this works in the game.
-Harbor gives +1 food on each sea plot, instead of giving +1 trade route and +25% trade route yield. Basically swapped the roles of Harbors and Lighthouses.
-Lighthouse gives +1 trade route, +25% trade route yield, and +1 commerce on each sea plot. Cost has been doubled, and Lighthouse requires Commerce tech to build (instead of Boat Building and Masonry). With both Harbor and Lighthouse, sea plots become the equivalent of a Grassland with a Village.
-Several buildings unlock additional specialist slots. In total, a city with all buildings would be able to employ 3 engineers and 4 of each other specialist.
~~Alchemist and Observatory each unlock 1 scientist specialist.
~~Fortress unlocks 1 engineer specialist.
~~Harbor and Vineyard each unlock 1 merchant specialist.
~~Holy Site and Library each unlock 1 artist specialist.
~~Tavern unlocks 1 spy specialist, though Security Bureau gave up 1 spy specialist. I did this so that spy specialists could be accessed earlier in the game, instead of waiting until you can build intelligence agencies and security bureaus.
~~Graveyard, Well, Public Baths, and Hospital each unlock 1 doctor specialist (from Expanded Great People mod).
~~Caravan House, Courthouse, Lighthouse, and Public Court each unlock 1 lawyer specialist (from Expanded Great People mod).
~~Palisades, Walls, Fortress, and Stable each unlock 1 drill sergeant specialist (from Expanded Great People mod).
-Several of the World Wonders (Mausoleum of Mausolos, Plato's Academy, Riches of Kroisos) were supposed to grant +1 happiness per 5% commerce rate, according to BuildingInfos.xml. However, in-game it only gave +1 happiness per 20% commerce rate. So, I changed each of them to +1 per 10% rate.
-National Epic previously gave a +15% Great People rate boost to all your cities. This would work out to about +1 GPP for every 7 GPP your city has, meaning only your GP farm cities would be likely to see even the slightest benefit. I increased the bonus of National Epic to +25% in all cities plus an additional +25% in the city it is built (encouraging you to build it in a GP-focused city, but also granting a slight benefit to all other cities).
-Made a few other minor changes to the wonders, including making sure each world wonder gives 2 GPP, and changing some of them to generate Great Doctors and Great Statesmen (from Expanded Great People mod). There are some other changes I'm working on to make the wonders more equal, as currently some of the wonders are extremely powerful (Hanging Gardens, Hypocratic Oath, etc.), while others are extremely weak (Oracle of Dodona, Temple of Artemis, etc.).
I probably made other changes, but I can't remember all of them. Once I finished tweaking the buildings, I planned on rebalancing the units (creating some sort of spearman unit for the later ages, making archers less weak, etc.).
There are also several other mods I think might work well in TAM:
Conqueror's Delight
Assimilation
Super Spies
BUG
