Very nice work! I have some suggestions though:
The "Sino-culture" names do not sound very interesting, nor historical. It looks very artificial, too. How about some changes like the Manchu case?
Sino-Vietnamese --> Jiaozhi
Sino-Tibetan --> Zang
Sino-Altaic --> Menggu
Sino-Korean --> Joseon or Chaoxian
Now almost all tags around Ming can benefit from the new changes, but Chagatai remains an exception. Maybe a change like the following can solve this issue:
Chagatai can form Liao when the following conditions are met: (Western Liao, 1124-1218 was a sinicized dynastic empire in central Asia, a successor state to the Liao dynasty of China)
- Primary culture changed to Uyghur
- Has converted to Buddhism
- Has controlled and cored all the Chagatai and Yarkand lands (in 1444 setup), and Hami, Yumen, Samarkand, Zhangye
Effect:
- Country name changes to "Liao"
- Becomes a monarchy and takes` government reform "Chinese Kingdom"
- Sinicize Uyghur culture to Huihu (Chinese name for the uyghur people before they converted to Islam) or Khitan-Uyghur
- Gain permanent claims on Mongolia and Manchuria regions, as well as West Gansu, East Gansu, Shaanxi, Shanxi, North Hebei and South Hebei areas
- Is an end-tag
- Gain new mission tree (a tree like the Manchu one)
- New ideas (can be very close to the Chagatai ones, but with a new name)
These conditions are almost impossible for AI but will add a lot of fun for players. It also has historical basis, at least to some extent.