Kizaru seems more like the mobster type like capon and from what I've seen samurai seems to have a strong sense of loyalty to their country and leader so I doubt mihawk is from wano simply because he would have gon to support them besides he would be one of the first few kinomen and momo would have searched outSakazuki, Sengoku, Fujitora, Kaido all sound like japanese names.
Wano appears inspired by the Shogun period of Japan so it makes sense.
We've also seen chapter covers of Akainu and Kizaru in robes that resemble japanese fashion.
Wano is also a place that is likely full of skilled swordsmen, so I wouldn't be surprised Mihawk was born there aswell.
Kuzan is probably not because he is black.