Before anything sorry for not reading all the comments.
That said Euro civs could use cards to allow hiring specific Merc units like Sweden, specifically mercs from their nations.
Ex, Germans: Blackritter, Jäger, etc.
French: Fusilier, Napoleon canons, etc.
Be a card or mechanic to allign with royal houses from new dlc. And be able to send it’s special units as shipments like Italians from Basilica.
Advanced mill.
In addition to the current benefits, all upgrades available at an earlier age and 20% cheaper.
Seed Drill
Moved to age 1.
Artificial Fertilizer
Moved to age 2.
Advanced plantation
In addition to the current benefits, all upgrades available at an earlier age and 20% cheaper.
Bookkeeping
Moved to age 2.
Homesteading
Moved to age 3.
Refineries
Moved to age 3.
I admit it’s fun to think of ideas, for “new” cards. 
Advanced Arsenal: Ships 1 Arsenal Wagon; Arsenal upgrades are 50% cheaper and provides Arsenals with Flint Lock, Paper Cartridge, Military Drummers, Pillage, Professional Gunners and Trunion.
Advanced Market: Ships 1 Market Wagon; Markets get +30% buy/sell factors and upgrades are 35% cheaper.
Advanced Ranching: Livestock Pens can train Cows and Livestocks fatten 30% faster when tasked to Livestock Pens, Farms, and Villages.
Advanced Trading Post: Trading Posts get a ranged attack and +30% hit points, and Trade routes generate 25% more resources.
Assassins: Upgrades Spies into Assassins with +100% attack and +5.0x multiplier against heroes and mercenaries; assassins gain a charged ability, Hidden Pistol.
Advanced Dock: Docks get +100% attack and heal ships 100% faster, and allows to recycle the fishing boats that are garrisoned. (ship train time -35%)
Advanced Citizenship: Removes the population cost of settlers and Fishing Boats.
Citizenship: Ships 1 Citizen (Settler) for each building you have constructed; Citizens enabled at the Town Center for 50 coin
OperaticShip743 for nothing in particular. 
Some “new” cards for ancient civilizations
The Fort and Castrametation cards need some improvements.
2 Fort Wagons: (Age IV)
Effect: Ships 2 Fort Wagons; Fort build limit +2
Castrametation: (Age III)
Effect: Ships 1 Fort Wagon; Fort build limit +1; the Explorer can build Outposts and Forts
Pioneers: (Age I)
Effect: Villagers get +65% hit points Ships 2 Settlers.
Town Militia: (Age I)
Effect: Town Centers get +50% attack, can use Colonial Militia and they only lose half of their health.
Reputation: (Age II)
Effect: Reduce the maximum experience scaling per consecutive shipment to 1250 instead of 2500.
I think that now that there are “natives” from Europe and Africa, the Europeans could have shipments of this type of units in their respective decks. Infinite send for the end of the game, and limited send for early ages.
food box needs buff.
villagers collect food is faster than gold and wood.
so many players I know don’t choose 700 food,600 food or 1000 food at all,that’s unfair.
maybe 25% buff is enough for shipment and tp.