So after sometime messing with the game mechanics and mods i managed to play as china with a lot of mods and in mod modifications
Mods that you will need:
-Umbra Spherae (to add far east)
-Everything Playable! China Edition!
-China Boon - Western Protectorate (to get boons from china)
-Better Imperial Chinese Government (to add chinese imperialism realism to game like protectorates)
DONT FORGET TO BACKUP YOUR MODS AND SAVES
Necessary mod modifications
Umbra Spherae will disable the chinese interactions, which will disable acquisitions of commanders, artifacts, trade contracts and etc.
So you will need to go to DocumentsParadox InteractiveCrusader Kings IImod and open the umbra spherae rar archive, then go to commonoffmap_powers and delete 00_offmap_powers.txt, that should enable the chinese menu again.
After that you are ready to start the game.
Beginning the game
Once you start your realm will be a mess, lots of vassals of county rank and oversized desmene, first ADOPT CHINESE IMPERIALISM, then deal with that creating kingdom titles and giving then to your vassals as viceroyalties, they will work as protectorates because of the Better Imperial Chinese Government mod, and they will work pretty much like a confucian bureaucracy.
After you managed your realm affairs, you should get your hands on the western protectorate which holds no lands in game, but their troops will always spawn on Jiuquan as in normal game, get the title using the console command : give_title e_china_west_governor *****, '*' being your char ID, you can check it by enabling charinfo and moving your cursor to your character. Since you have china boon you will be able to get everything you need, and you will control 2 empire titles, always set your first empire as your primary title, never play with the protectorate as your primary title for too long, otherwise you will revert to feudal or worse, and everytime you want to get chinese boons just set the protectorate as your primary title, get what you want and go back to your regular empire.
Some notes about China:
The emperor of china won't do anything, he won't even appear in game, so consider yourself as the de facto ruler of the dragon throne. Everything china takes will be yours. From time to time the game will start a war like if you were the protector general, sometimes you will get event troops.
Here are some commands for china:
add_offmap_currency offmap_china X /// X being the number of grace you want
set_offmap_policy offmap_china X /// X being china_isolationist china_open china_expansionist
set_offmap_status offmap_china X /// X being china_stable china_unrest china_civil_war china_mongol_invasion
china_jurchen_invasion china_famine china_plague china_golden_age
One more thing:
For some reason you cannot assign commanders yourself on umbra spherae, so just ask china for commanders and assing then immediately or promoto a commander and do the same.
THATS ALL FOLKS, I WISH I WAS HELPFUL, IF SOMETHING GOES WRONG POST IT HERE AND I WILL SEE WHAT CAN I DO