This looks interesting.
My current summary on the subject is about this. It is not super up-to-date, and there will certainly still be some oversight.
All
→ Improve the accuracy of the ‘Town Centre’.
→ Increase the cost of the ‘Fortified Church’ from 200 W to 225 W.
Armenians
→ Swap ‘Multe Cart’ for ‘Mining Camp’ and ‘Lumber Camp’.
→ Remove ‘Mule Carts cost -25%’.
→ ‘Mule Cart Mining Camp and Lumber Camptechnologies are 40% more effective’.
→ Add ‘Fortified Church cost -20%’.
→ Move the ‘Long Swordsman and above, and Spearman line available one Age earlier’ to the Dravidians.
→ Remove ‘Galley-line and Dromons fire one additional projectile.
→ Add ‘Fishing Ship are produced 25% faster’ as Civilization bonus.
→ ‘Cilician Fleet’: Demolition Ships +20% blast radius; Galley-line and Dromons +1 range fire one additional projectile’.
→ Move the current effect of ‘Fereters: Infantry (except Spearman-line) +30 hit points, Warrior Priests +100% heal speed’ to Georgians.
→ Add ‘Fereters: Mounted units regenerate 15 hit points per minute’ from Georgians.
→ Move the current ‘Team bonus: Infantry have +2 Line of Sight’ to Dravidians.
→ Add ‘Team bonus: Docks provide +5 population space’ from Dravidians.
Recap:
→ Fishing Ship are produced 25% faster.
→ Mining Camp and Lumber Camp technologies are 40% more effective.
→ Fortified Church cost -20%.
→ First Fortified Church receives a free Relic, it does not affect the Relic Victory.
→ ‘Cilician Fleet’: Demolition Ships +20% blast radius; Galley-line and Dromons fire one additional projectile.
→ ‘Fereters’: Mounted units regenerate 15 hit points per minute (moved from Georgians).
→ Team bonus: Docks provide +5 population space (moved from Dravidians).
→ Swap ‘Arbalester’ for ‘Heavy Cavalry Archer’.
→ Add ‘Parthian Tactics’
→ Add ‘Camel Rider’.
→ Add ‘Paladin’.
→ Swap ‘Ring Archer Armor’ for ‘Plate Barding Armour’.
→ Add ‘Shipwright’.
→ Add ‘Siege Engineers’.
→ In conclusion, they should be ‘Cavalry and Naval civilisation’.
Aztecs
→ Villagers carry +3 +4.
Bohemians
→ ‘Mining Camp technologies Gold Mining and Gold Shift Mining are free’.
→ Add ‘Hoardings cost -50%’ as Civilization bonuses (look at the unique castle they have).
Britons
→ ‘Yeomen’: +1 foot archer range; +2 tower attack Archery Ranges work 10% faster.
Burmese
→ Move the ‘Infantry +1 attack per age (starting in the Feudal Age)’ to Celts.
→ Add ‘Elite Battle Elephant upgrade is 50% cheaper’ as Civilization bonuses.
→ Move ‘Relics are visible on the map from the game start’ from Team bonus to Civilization bonuses (shared exploration is active by default).
→ Add ‘Knight units and elephant units have +2 attack against standard buildings’ as Team bonus.
Reacap:
→ Lumber Camp technologies are free (unchanged).
→ Battle Elephants have +1/+1 armor (unchanged).
→ Elite Battle Elephant upgrade and Monastery technologies are 50% cheaper.
→ Relics are visible on the map from the game start.
→ ‘Manipur Cavalry’: Gives cavalry units +4 attack against archers (unchanged).
→ ‘Howdah’: Gives Battle Elephants +1/+1 armor (unchanged).
→ Team bonus: Knight units and elephant units have +2 attack against standard buildings.
Byzentines
→ Fix the voice lines (thread).
→ Byzantine architecture set (can be shared with other civilisations).
→ Team bonus: Monks heal 100% 80% faster.
Dravidians
→ Add ‘Long Swordsman and above, and Spearman line available one Age earlier’ from Armenians.
→ Move the current Team bonus ‘Docks provide +5 population space’ to Armenians.
→ Add ‘Team bonus: Infantry have +2 Line of Sight’ from Armenians.
→ ‘Fishing Ships carry +15 (except Fish Traps)’.
Reacap:
→ Receive 200 wood when advancing to the next Age (unchanged).
→ Fishermen, Oyster gatherers, and Fishing Ships carry +15 (except Fish Traps).
→ Barracks technologies are 50% cheaper. Long Swordsman and above, and Spearman line available one Age earlier (from Armenians).
→ Siege units cost -33% wood (unchanged).
→ Skirmishers and Elephant Archers attack 25% faster (unchanged).
→ Medical Corps: Elephant units regenerate 30 hit points per minute (unchanged).
→ Wootz Steel: Infantry and cavalry attacks ignore armor (unchanged).
→ Team bonus: Infantry have +2 Line of Sight (from Armenians).
Georgians
→ Give the ‘Warrior Priest’.
→ Move ‘Mounted units regenerate 5/10/15 hit points per minute in the Feudal/Castle/Imperial Age’ to Armenians.
→ Move ‘Aznauri Cavalry: Mounted units take 15% less population space’ to Civilization bonuses.
→ ‘Svan Towers’: Defensive structures receive +2 +3 attack. Towers deal pass-through damage.
→ Add ‘Aznauri Infantry’: Infantry (except Spearman-line) +30 hit points, Warrior Priests +80% heal speed (from Armenians)
Reacap:
→ Start the game with a Mule Cart (unchanged).
→ Fortified Churches provide +10% work rate to Villagers (unchanged).
→ Mounted units take 15% less population space.
→ Units and buildings receive -20% damage when fighting from higher elevation (unchanged).
→ ‘Svan Towers’: Defensive structures receive +3 attack. Towers deal pass-through damage.
→ ‘Aznauri Infantry’: Infantry (except Spearman-line) +30 hit points, Warrior Priests +100% heal speed (from Armenians).
→ Team bonus: Repairing buildings costs -25% resources (unchanged).
→ Give the ‘Camel Rider’.
→ Swap ‘Parthian Tactics’ for ‘Thumb Ring’.
→ Swap ‘Bracer’ for ‘Ring Archer Armor’.
→ Increase (Elite) Monaspa hit points from 70 (80) to 80 (95).
Goths
→ Remove ‘Villagers +5 attack vs. wild boar’.
→ Remove the Gunpowder Units and improve historical accuracy. For example:
→ Swap ‘Hand Cannoner’ for ‘Thumb Ring’.
→ Swap ‘Bombard Cannon’ for one of ‘Siege Ram’, ‘Siege Onager’ and ‘Siege Engineers’.
→ Swap ‘Plate Barding Armor’ for ‘Hussar’ and ‘Husbandry’.
→ Find a more proper name for ‘Huskarl’.
Huns
→ The Hunic Horse cannot convert herd animals.
→ Add (Elite) Steppe Lancer.
→ Cavalry Archer and Steppe Lancer cost -10% Casle Age, -20% Imperial Age.
Italians
→ Rebalance the ‘Genoese Crossbowman’ (thead).
→ Rebalance the ‘Condottiero’ (thread).
→ Backport the Galeazza from AoE3.
Khmer
→ Move ‘Scorpions have +1 range’ from Team bonus to Civilization bonuses.
→ Add ‘Elephants have +2 Line of Sight’ as Team bonus.
Poles
→ Increase ‘Obuch’ cost from 55F 20G to 55F 25G.
Mongols
→ Fix the ‘Mangudai’ bonus damage (thread).
→ Move ‘Lost houses do not drecrease population headroom’ to Civilization bonus.
→ Move ‘Scout-line and Steppe Lancer +30% HP’ to ‘Nomads’ Unique technology.
Sicilians
→ Farm upgrades affects existing Farms and provide additional +125% +50% food.
→ Hauberk: Knights Barracks and Stable units +1/+2P +1/+1P armor.
Teutons
→ Make the ‘Crusader Knight’ a unique unit upgrade like the ‘Savar’ (thread).
Turks
→ Add (Elite) Steppe Lancer.
→ Sipahi: Mounted archers and Steppe Lancers +20 hit points.