Regarding the use of the word among black men to mean "buddy", sure, my older Italian relatives used to call each other "wop" as a in-group term of affection. But woe to any non-Italians who called them that!
I wouldn't question that - the point was that a discussion of the words themselves in a clinical sense carries no pejorative meaning (and even their intended meaning can vary according to context).
It's unfortunate for the purpose of this discussion that the author chose "N-word" as his example. It would have simplified matters if he had chosen "F-word" or "C-word" given that all modern profanity in the linked article has been reduced to euphemism, as my question wasn't about racial labelling per se, but rather about the need to reduce any (modern) profanity to 'X'-word when discussing the words themselves, as distinct from using them for their implicit meaning.
One would absolutely refrain from using racial labels in a pejorative context. However in a discussion of the meaning or history of the words themselves (racially linked or not), their use is unambiguously not profane. One only has to consult an authoritative dictionary to confirm that these words do in fact exist, and can be used in an uncensored form without causing offence.
Who decides what a word means and when? Has a dictionary ever defined the complex web of emotions tied to that or any other hateful slur? Can the OED tell you what it feels like for a person of color to hear it, even in supposedly clinical circumstances?