If Japan catches you, however, that's an automatic loss of Japanese citizenship. Japan has a specific law that says if you voluntarily acquire (or re-acquire; it doesn't distinguish) a foreign citizenship as an adult you immediately lose your Japanese citizenship.
And if you lose your Japanese citizenship, you go back to being a foreigner. Without a visa. Meaning you risk losing your ability to live and work in Japan.
As most people who naturalize do so because they've established deep for-life roots in Japan, their Japanese citizenship is not something they're willing to gamble.
The "Japanese language requirement" is technically part of requirement 4... the rational being that if you can't understand Japanese and you aren't wealthy enough to support yourself without working for the rest of your life, you are too dependent on English language workplaces. While they exist, they are a tiny niche of Japanese society in the bigger scheme of things.
In particular, starting at 1m04s, the interviewer says "I hear it's hard to become Japanese". And the naturalized person answers, "the more and more I read about it on the English net, I realized there's so much misinformation about it that you really couldn't trust anything that was written English about naturalization."
He's talking about people like you. He spends the whole video in particular debunking almost every point you made.
> heredity and skin color most definitely has something to do with the japanese ethnicity.
Only to racists. Just as being Jewish is an ethnicity (as well as a religion), you don't have to be white or have Jewish parents to be of Jewish ethnicity.
More and more Japanese Nationals with mixed race are born all the time, and raised completely in Japan and only speak Japanese, yet would "pass as white."
And when they're famous and appear in the media, they are considered by most of the Japanese audience to be ethnically Japanese.
On the other hand, there are quite a few Japanese-Americans whose parents are both racially "100%" Japanese, yet because they speak awful or nonexistent Japanese and or "act American" or "have American values", are not considered to be ethnically Japanese.
The interesting thing is that in Japan, for baseball, they forcibly separate the home fans and the visitor fans into separate areas. And the cheering is relegated so each side has the opportunity to cheer (while they politely stay quite when it's the other side's turn).
And if you lose your Japanese citizenship, you go back to being a foreigner. Without a visa. Meaning you risk losing your ability to live and work in Japan.
As most people who naturalize do so because they've established deep for-life roots in Japan, their Japanese citizenship is not something they're willing to gamble.