Burgundians:
Economic upgrades available one age earlier: I honestly have no idea how this will play out. The wall nerf means going fc with eco upgrades is a very risky strategy. In Dark Age you will probably want to get to Feudal and military faster and similarly in Feudal Age you will probably want to get to the Castle Age powerspike instead of sinking resources into Feudal. One situation where this could be strong is in a all in Feudal or while going up which will give you a minimal advantage.
Stable techs cost 50%: The only reason I dislike this is because they have Paladin. Get rid of Paladin and this is fine.
Cavalier available in Castle Age: Again the only reason I dislike this is because they have Paladin. Getting Cavalier in Castle Age or on the way up then getting Paladin for 50% off as soon as you hit Imp just seems ridiculous.
Gunpowder units have 25% more attack: Nothing to say. Seems ok.
Coustillier: Now this is a fun unit but also very OP. There are a few ways to balance this:
1) Reduce the charge attack or increase the time between charges. This will turn it into a knight which gets super strong every couple of minutes.
2)Keep the charge as it is and reduce the base stats and make it more of a glass cannon. This way its function will be more like a monk: charge in when you're filled with charge juice, kill stuff then get out and repeat. I personally prefer the second idea since it adds more micro and gives the unit some identity.
Flemish Militia and Revolution: Another fun unit and a fun tech. I think it could be slightly broken since you could potentially have an extra 100+ military units and just straight up win. I don't really know how you would balance it apart from increasing the cost of the tech.
Burgundian Vineyards: Another situationally broken tech. Burgundians have hussar and when you hussar spam you usually have upwards of 80 farmers. Now I haven't personally tested this but several people have said that 40 farms generate roughly the same amount of gold as a relic. 80+ farms will give you two relics + whatever relics you already have, which would be a decent amount of gold income in ultra lategame. Also a lot of food is typically stockpiled with that many farms and a well timed Burgundian Vineyards tech could give you the gold to switch into Paladin. Now if you don't have that many farms it isn't really a problem.
Team Bonus: No thoughts. It's normal.
Sicillians:
Castles and TCs built 100% faster: Interesting bonus. Makes them a top tier nomad and Daut civ.
Land Military units take 50% less bonus damage: Another interesting bonus. Probably will be nerfed since it makes it extremely difficult to counter whatever they're making, instead of allowing the units to survive longer against the counters.
Farm upgrades provide 100% additional food: An extremely strong bonus. Pretty much doubles the effect of all the farm upgrades. Might be nerfed, might not be.
Donjon: I like this since I was expecting another Krepost but it is different plus the Sicillians don't get towers. Personally I believe that once the dust settles we will see these things used defensively more than offensively since they have good range and can make the tanky Serjeants. They can obviously be used offensively but I don't think we'll see them much that way.
Serjeants: Interesting unit. Seems to be basically a stronger version of the militia line in each respective Age and so will be weak to similar things. Its armour might have to be nerfed slightly, maybe take away 1 pierce armour but apart from that it seems to be fine.
Both Unique Techs: The thing I dislike about both of these is that they can only be used once which I don't think is Age 2's style. They both might end up getting nerfed slightly or reworked but apart from that I really have nothing to say about them.
Team Bonus: Turns Transports into Rams. Not much else to really say.
These are my two cents. Please take whatever I say with a grain of salt since I'm just a 1500 but if you agree or disagree feel free to tell me why. Thank you for reading.
Economic upgrades available one age earlier: I honestly have no idea how this will play out. The wall nerf means going fc with eco upgrades is a very risky strategy. In Dark Age you will probably want to get to Feudal and military faster and similarly in Feudal Age you will probably want to get to the Castle Age powerspike instead of sinking resources into Feudal. One situation where this could be strong is in a all in Feudal or while going up which will give you a minimal advantage.
Stable techs cost 50%: The only reason I dislike this is because they have Paladin. Get rid of Paladin and this is fine.
Cavalier available in Castle Age: Again the only reason I dislike this is because they have Paladin. Getting Cavalier in Castle Age or on the way up then getting Paladin for 50% off as soon as you hit Imp just seems ridiculous.
Gunpowder units have 25% more attack: Nothing to say. Seems ok.
Coustillier: Now this is a fun unit but also very OP. There are a few ways to balance this:
1) Reduce the charge attack or increase the time between charges. This will turn it into a knight which gets super strong every couple of minutes.
2)Keep the charge as it is and reduce the base stats and make it more of a glass cannon. This way its function will be more like a monk: charge in when you're filled with charge juice, kill stuff then get out and repeat. I personally prefer the second idea since it adds more micro and gives the unit some identity.
Flemish Militia and Revolution: Another fun unit and a fun tech. I think it could be slightly broken since you could potentially have an extra 100+ military units and just straight up win. I don't really know how you would balance it apart from increasing the cost of the tech.
Burgundian Vineyards: Another situationally broken tech. Burgundians have hussar and when you hussar spam you usually have upwards of 80 farmers. Now I haven't personally tested this but several people have said that 40 farms generate roughly the same amount of gold as a relic. 80+ farms will give you two relics + whatever relics you already have, which would be a decent amount of gold income in ultra lategame. Also a lot of food is typically stockpiled with that many farms and a well timed Burgundian Vineyards tech could give you the gold to switch into Paladin. Now if you don't have that many farms it isn't really a problem.
Team Bonus: No thoughts. It's normal.
Sicillians:
Castles and TCs built 100% faster: Interesting bonus. Makes them a top tier nomad and Daut civ.
Land Military units take 50% less bonus damage: Another interesting bonus. Probably will be nerfed since it makes it extremely difficult to counter whatever they're making, instead of allowing the units to survive longer against the counters.
Farm upgrades provide 100% additional food: An extremely strong bonus. Pretty much doubles the effect of all the farm upgrades. Might be nerfed, might not be.
Donjon: I like this since I was expecting another Krepost but it is different plus the Sicillians don't get towers. Personally I believe that once the dust settles we will see these things used defensively more than offensively since they have good range and can make the tanky Serjeants. They can obviously be used offensively but I don't think we'll see them much that way.
Serjeants: Interesting unit. Seems to be basically a stronger version of the militia line in each respective Age and so will be weak to similar things. Its armour might have to be nerfed slightly, maybe take away 1 pierce armour but apart from that it seems to be fine.
Both Unique Techs: The thing I dislike about both of these is that they can only be used once which I don't think is Age 2's style. They both might end up getting nerfed slightly or reworked but apart from that I really have nothing to say about them.
Team Bonus: Turns Transports into Rams. Not much else to really say.
These are my two cents. Please take whatever I say with a grain of salt since I'm just a 1500 but if you agree or disagree feel free to tell me why. Thank you for reading.