Look at China and Asia today; there are the effects. China, with it's quite exaggerated population would have formed an economic powerhouse. It's industrial and agricultural production would have overtook western societies. Along with industrial modernization, the Qing military would be a major power in the world.
China had lots of vassal and tributary states in Asia like Korea, Vietnam, Tibet... This states would be chinese "colonies" (notably to sell the products of China's 19th century industry). And China would have to deal with some unpleasant neighbours: Russia in the north, Great Britain in the west, the US in the east and Spain in the south.
Japan, modernized or feudal, would be a trade partner, surely a competitor, but likely not an enemy; China has no interest in attacking Japan; Japan would know that an attack on Korea (and thus China) would be suicuide.
A big problem in China's society would be liberalism and republicanism, trying to overthrow monarchy; concurrently, the feudal lord would attempt to stop political modernization, leading into a civil war.
The modernization of China (and probably it's democratization) would be a problem in India: the people there would surely try to expel the Brits and to build their one modern society.