I could get so bad that we’re no longer to say Nip it in the bud!.
Nope. This is incorrect. Many, if not most, if not damn nearly all of the Americans fighting the Japanese in WWII hated them. Admiral Halsay was famous for putting up a sign which said “Kill japs, kill japs and kill more japs.”
This is also incorrect. Please see my post above.
The word comes from two characters, 日* nichi* which means the sun and 本 hon which means origin. When two characters are combined, the second character often becomes voiced through a process called rendaku. H’s become either b’s or p’s. K’s become g’s, etc.
The Japanese call their country both Nihon and Nippon, so it is what they call their own country.
There are a set of rules where one tends to be used in certain cases where the other tends to be used in other cases. The government currently uses Nippon on stamps, for example. You rarely (if ever?) hear nippongo (Japanese language) although you will hear Nipponjin (Japanese person).
I’m not familiar with any past racial or ethnic slurs that are now considered inoffensive terms for that racial/ethnic group, but “gay” was once a derogatory term for homosexual men. “Queer” was also once pretty insulting, and in some contexts still is, but has to an extent been reclaimed.
As for “Nip” in particular though, I don’t see any point in bringing it back. And that’s not just because it’s offensive, but because it doesn’t seem useful as anything but a slur. It’s shorter but far less clear than just saying “Japanese”. The term “Nip” has no obvious relationship to the English word “Japanese”, and “nip” is both a fairly common English word with a meaning (pinch/bite) totally unrelated to Japan AND a slangy shortened form of “nipple”. So using “Nip” instead of “Japanese” could lead to confusion in some contexts, and the association with “nipple” makes it likely it would seem insulting even if the past were entirely forgotten.
It depends.
Are we talking about the tip of a breast?