I am not talking about ethnic minorities who reside in southern China today. I am only talking about southern Chinese who consider themselves Hans.
Bottomline is, it's next to impossible to find out every southern Han-Chinese's genetic percentage of Han vs Yue (if such definitions can even be set in the first place as both are genetically diverse groups) and then tally them together and come up with an average. What we know is there have definitely been interbreeding between Han settlers from the north and those who are native to southern China, again, we won't get into the percentage as it's nearly impossible to say.
Point is though:
1.) Modern southern Han-Chinese consider themselves Han because they have northern Han blood as well as that of that natives of southern China.
2.) Modern southern Han-Chinese obviously practice Han culture and use Han language.
So how exactly would one justfiy the claim that modern southern Han-Chinese are Hanized natives, as implying that modern southern Han-Chinese aren't really Han-Chinese. Of course, we're not even getting into the claim that MSHC are Yues and that they should "reunite" with Vietnam...
No such thing as a complete Han Chinese. What do you mean about Han-Culture? In the South, they have Dragon Boat festival as from the NOrth? I don't think so. The some of the Han culture is blending in with the Southern cultures, including Vietnamese.
Please check back with the Han language thing my friend. The written language in the past was different in some ways from nowadays. I believe that the Han language was close to the Yue. The disappearance of the written Yue language was probably due to political control. You sound like the Yue was an empty land and everything was displaced by the Hans from the North.
If the Bai Yue unite together, it's a normal thing and probably won't happen at my age but until the enlightenment age when everyone is realizing the true of Han Chinese.