You realize a term can have multiple meanings, right?
I have had some experience in the etymology of the term "******", and here is what I have learned. It is probably the most offensive term in the English language as a term for a black person, and has become dramatically more so in the last thirty years. It first appears in English around 1640, imported from the French or Spanish words for "black". By the mid 1700's it had become a common but offensive term for black people.
"Negro" is literally the Spanish word for the color black, and when imported into English took on the meaning of a black person. Well into the latter parts of the twentieth century it was common to find scholarly works dividing humanity into Caucasoid, Negroid, and Mongoloid races. This was thought at the time to be both "scientific" and neutral, reflecting no value judgments.
I learned from an uncle born in 1900 that some American dialects (in his case Wabash valley) had trouble enunciating "Negro" and substituted for it "Nigra". This offshoot was considered by its speakers as the equivalent of "Negro" and without offensive intent, but inevitably its closeness to "******" caused it to be treated by many as highly offensive.
From my childhood I have always had a foot in the black community in the Midwest and in the early 70's I taught at an historically black college and lived on campus. The term "******" was used in the black community very commonly and they regarded its usage in a wide range of contexts. It was always considered inappropriate to use in formal or polite situations, in church, around elders, in front of white people, etc. Sometimes it was used as a joking or mildly derogatory term among blacks in private. When used by white people it almost always was considered offensive, although children were taught from an early age to not take visible exception to white racism because of the Emmitt Till-type consequences. And of course from the 60's on the word acquired some shock value and began to be used gratuitously by black people for that effect.
There is another use of the word "******" commonly used by educated blacks and which I found impossible to avoid in teaching. There are a number of cultural terms with no substitute that involve the word: CNIC (chief ****** in charge), "playing ******", "playing dumb ******", "****** hunting", "******-lover", and so forth.
Of course there are bound to be local and regional variations, and I suspect I have hit only a few high points (or low points!). My experience is that white people should be very careful in using these terms, use them only with black people they know well enough to know if they would be offended, and never to use the words in a group of only white people.
Peace all.