A united and free Korea under Chinese KMT supervision likely industrializes later and less so than OTL South Korea. She is effectively part of the Chinese Sphere of influence and remains that way for most of a generation before trying to regain her independence. China probably drags their feet if they allow it at all. Indochina likely plays out in a similar manner at first until the equivalent of the Vietnam War of OTL (ironically along an opposite geographic pole) sees China lose all manner of troops to attrition with resultant massacres among the Vietnamese only fueling the flames of nationalism further and further.
The real question is how far does a free China go during the Cold War. I see either an economy about the size of West Germany's versus one eventually rivaling the US itself depending on leadership and severity of corruption. Hong Kong, Macau, and Taiwan lose their OTL significance to Shanghai, Guangzhou, and Nanking among other places.