Were there any portions of Korea that could have similarly undergone such a thing? I'm guessing no, barring very different invasions.
Portions of Korea did undergo the same thing, unless you're referring to the thousand-year aspect. Northern Korea could have been held more firmly by early dynasties. If it had, inevitably a later (probably medieval) dynasty would seek to conquer the remainder of the peninsula.
I just find this very interesting because out of the all the polities on the periphery of China (Tibet, Manchuria, Mongolia, Burma?, Taiwan, etc.), Vietnam was the one that was ruled over the longest. It truly is the one that got away. I guess that's a testament to both the independent-mindedness of the Vietnamese people living there, and the ferocity of guerrilla jungle warfare.
Not really, no.
The independent-mindedness basically didn't exist for a thousand years. Then came the 5 Dynasties 10 Kingdoms period, when Annam was "independent-minded" in exactly the same sense as all the other southern provinces - local elites saw that they could set themselves up with their own petty kingdoms because the peasants didn't care enough. Then the Song reunited China but - for no particularly inevitable reason - declined to try to reincorporate the province.
Then the Vietnamese
began to become truly independent-minded, because China was treating them as such.
I think it's hard to say because it's complicated to make projections involving huge populations and so forth, but I'd imagine that Nanyue would end up like Fujian, Guangdong, Guangxi, Yunnan, etc., a province full of restive natives who slowly Sinicize over the centuries. Except with more jungle. And maybe more rebellions.
Not like Fujian or Guangdong. If Guangxi wasn't properly sinicized, there's no reason to think the fewer and later colonists passing it to reach a reconquered Annam would do any better.
Not like Yunnan, either. Yunnan was full of a huge diversity of peoples, almost all oriented in part towards mountain and high-valley societies. This left an opening for Han and Hui (Muslim Han) immigrants to swamp the low valleys with Chinese-style intensive agriculture. The Vietnamese were one major ethnic group located
only in the good rice country. Even today, Vietnamese majority areas are just under half the land area of that skinny little country, because they almost exclusively live in the coastal lowlands. Though I suppose you could argue that those same highland bits of the province would be somewhat like Yunnan.
Vietnam would be like Guangxi, if it had never been left out in the cold by a united dynasty. You'd have a large minority province, the population of which takes for granted that they're Chinese, though in a lot of ways they truly aren't.
Very little of the OTL system of "Chinese" characters made up for the Vietnamese words with no Chinese equivalent. Instead they'd make do with the written language of the empire.
