UU: Fire Lancer (Pikeman)
Available at Metal Casting (1 tech earlier)
17

CS (up from 15)
Pyrotechnics (-20 % CS/RCS for all hostile mounted units within two tiles and -5 % CS/RCS for all other land units ; doesn't stack)
Splash Damage
No bonus against mounted units
Treated as a gunpowder unit (probably not relevant for anything)
One of the earliest forms of gunpowder weapon. In modern term, the Fire lance was a normal spear with a shotgun cartridge strapped to the end. This single gunpowder charge had a range of no more than 3 meters, but could give a crucial 'shock' advantage at the beginning of a melee engagement.
Is there any reason these were moved up a tech level? The first recorded deptiction of a fire lance is 950 AD, and they became widespread by the 12th century. They were still widely in use during the Mongol Invasion. I don't see much reason to move them into classical.
UB: Examination Hall (Chancery)
Unlocked at Education
+1 paper
2 Civil Servant specialists (up from 1)
+10%

to diplomatic units
+5

promotion on diplo units built here
5% of current

production added to production as an instant boost on

citizen birth
+5%

Great People rate in the city, increased to +10% during WLTKD
Whenever a citizen is born in the city, gain 30

GPP towards a random Great Person, scaling with era
UW: Siku Quanshu (Hermitage)
Unlocked at architecture
Requires Chancery in city
Grants a free

Great Writer
+25%

Great Writer rate in all cities
+3

Science to Universities and Chanceries, and +3

Culture to Great Works of Writing
4

Great Work of Writing slots (instead of Art)
+10

Science,

Culture and

Gold when themed with writing from different eras
Xiafan Guanjun - (Frigate)
Unlocked at Astronomy (1 tech earlier)
400

(25 more than Frigate)
36

RCS (2+ than frigate)
30

CS (10+ than frigate)
Great Generals I promotion
'Kowtow' promotion (2

CS influence every turn when in city-state border)
Broadside Promotion (+40% vs cities)
The largest junks ever created, and more than twice the size of any ships the Europeans were building at the time, the Ming Dynasty's
legendary 'treasure fleet'. Led by the great Zheng He, the
Xiafan Guanjun undertook 7 treasure voyages. On these voyages they deposed monarchs, destroyed pirate armadas, transported diplomats and even abducted kings to make tribute and pay homage to the emperor of China. These voyages greatly extended the Chinese sphere of influence, and made vassals and suzerains of dozens of smaller, client states.
UU - Red Guard 
Infantry replacement
I'm not seriously considering this option, it's much too late to be fun, and I'd rather keep things with dynastic China, rather than the PRC. This echoes my preference to keep England "english". Keep China "Imperial"