Agree but I think China, Christianity and Islam are the prime examples. USA use culture as trading goods mostly which certainly has worked in terms of spread but then Swahili should be included as well, no?

Any definition of imperialism that miss the Mongols is silly in my mind. Percentage of humanity is related to someone who lived 800 years ago but this is somehow not worth mentioning.

Was it limited to China or is China the region that it was applied to. There was no line in the ground or on a map that said China back then.

I really have to squint to see the differences you seem to be seeing. The Arab conquest not spreading identity? How about the Aztecs? Half of Europe speak Latin languages somehow. The Roman colonists were different to later colonist how? Roman law had no impact on local tradition I presume?