Languages
In the Japanese Pacific States and Greater Nazi Reich wouldn't English be banned and Americans be forced to learn Japanese or German the same way the indigenous people of the Americas had to learn the language of their invaders.
shareI think they'd be pragmatic about it, pushing German or Japanese through the education system and making them necessary to get promoted beyond a certain point.
The Germans in particular would feel no need to eliminate other "Aryan" languages. It would make more sense for them to take the view that they were restoring the "pure" form of their Western subjects' cultures, but wanting them to be competent with German for convenience sake and a recognition of German victory.
The Japanese seem to be fond of many aspects American culture and probably want to preserve the parts of it that aren't a threat to them. In the book, when Tagomi goes to the other San Francisco, he's doesn't like how new architecture and the highway system have spoiled things he liked about the city's classic look.