I've one - what about a later Ming collapse , coupled with Russian intrusions into Manchuria later in the 17th or early in the 18th Century ? With the Manchus preocupied with warding off Russian incursions , China is left unconquered , and hence Balkanises , ala Mughal style ( Now , there are many differences - like the fact that Chinese Balkanisations lasted no more than a few centuries.) During this period , Western Powers begin intruding and intefering with the internal affairs of the warring Chinese sucessor states.
As a result ," Oriental " or " Chinese " comapnies will be formed and run like East Indie Companies . The result - by the early 19th century , large parts of the Chinese coast have been contested ( and the napelonic wars might be butterflied away , and the French Revolution ... ) in various wars between Major European Powers like Spain , France , Britan and Russia ( in the Northeast) .
By the dawn of the 20th century , most of China , with the exception of several rump satallite states in Western Sichuan , Gansu ,Xinjiang and parts of Mongolia are under western colonial domination .
By the early 21st century , anti Colonist fanatics will be the Al quadea analouge of this ATL ( not in terms of ideology , but in actions,)