Some of these are old posts, but I wanted to comment them anyway.
I agree. The more I thought about it, the more I like the idea of 1/2 priced markets or grocers. Grocers might be a bit much with the health bonus, but Julius Caesar with 1/2 markets could be...strong. Anyways, the reason I like it is it doesnt involve warring, and it fits thematically with taking over and exploiting other civ's economies. Dont believe me?
I like the idea of DPS Markets and Grocers, especially when both Roman leaders are Imperialistic now (in BTS). That would also make Cyrus more interesting choice compared to Darius I. DPS Customs Houses suggested in other thread would be good too, but I've started to think that Portugal with DPS Feitorias could be a little too powerful.
Maayybbee it should be the other way around: can build Warlords and Military Academy right from the begining and make the Instructor (+2xp) available only after Education. That would both help the aggressors (having to make Military Academy for production or Warlords for xp), 'help' balance out Cyrus and Julius if they had a true +100% GG emergence and balance out Cyrus's Charismatic effect on the Imp trait. One wonders why they didn't do that in the first place. It's the instructors that unbalance the early game - particularly for Aggressive leaders (who loose out) and Charismatic leaders (who win out).
I don't think it's a good idea to make a great specialist type allowed after a tech is researched. I think that possiblity to make your great people settled as great specialists (and gain extra benefits with Representation and The Sistine Chapel) should always be available.
Pre-BTS post:
How about -25% city upkeep?
Would've been really good improvement in Warlords, but now it would make Charlemagne have no maintenance costs in all his Rathaus cities. He could make cities all over the world with 4 corporations, and pay no maintenance. We would talk about unbeatable leader after he gets Code of Laws and can start making cities everywhere there is an empty space for a settlement without any limit.
For last, my suggestion:
+100% GG emergence (either Watiggi's 60XP needed for every GG or then (maybe a little weird possiblity) you could get two GGs instead of one every time you reach the limit (limits would be unchanged))
+50% production and food for Settlers and Workers (Expansive would get +1 food in all cities because of the lost Worker bonus and maybe DPS Hospitals, would it be overpowered?)
Double production speed for Markets, Grocers (DPS Jails suggested would go to Organized trait)
I'm glad the Ger actually represents the Mongolian cavalry doctrine, because none of the traits in the game boost cavalry.
My favored strategy for improving the Imperialistic trait is either increasing either existing bonus, giving them double production on Monuments (hey, it seems to fit the theme)
About Gers, I think that they should be giving +5XP (+3XP extra) for Mounted units because Totem Pole gives extra +3XP to Archery units too. Bug that obsoletes them with Rocketry instead of Advanced Flight should also be fixed. Keshik should also be buffed, because it isn't as great as it should be, and changes to Imperialistic trait would only benefit Genghis Khan, not his grandson Kublai Khan.
About Monuments, the bonus would have no real benefit for Catherine the Great, and if you're going to make Monuments all over the empire, you should build Stonehenge to get them free, I think (I guess you would build or capture at least eight cities before Astronomy if you choose an Imperialistic leader).