I don't think Japanese are closer to Amerindians or Inuits than from Korean and Chinese (and even South-East Asian). Physically they are much closer to Korean and Chinese. SE Asian have darker skin and can be divided in subgroups. Cambodian have very dark skin, but not Vietnamese. Real Thai have brown skin, but many are white because of Chinese imigration (especiallu\y in Bangkok).

I read that Indonesians, Malays, Philipinos and Polynesians were all originally from South China and then migrated by boat.

Japanese can't be from the same Northern Mongoloid group as Ameridians because Ameridians went to America about 10.000 years ago, while even Han Chinese only invaded China from Mongolia only about 3000 years ago. Then, there were no other way than crossing from Korea before the first civilizations (2000BC in China) and the development of proper boats/ships.

Have a look at American Indians from Inuits to Sioux, Cheyenne, Apache, Aztecs, Caribi, Tupi and Quechuas. Eventhough they were the same original group of migrants and it took no longer than 1000 years for them to spread from Canada to Chile/Argentina, they now look very different physically, but all have darker skin. If any of those people had lived in Jomon in Japan, they are probably extinct and surely haven't mixed with further migrants from Korea and China who are present day Japanese.

The ear wax thing is certainly just a matter of climate (even if its in the genes, it could change after a a only few hundred years, like physical features).