If you think that the n-word is only used to harm others then I assume you haven't listened to any late 20th and 21st century music. Context matters. That said, its use to racially insult people is shameful and not something I support.
That's a great point, I didn't think about that. It seems like it might be difficult to prove whether or not people had an intent to harm when you allow this kind of speech though.
Do you feel that speech intended to harm should be prevented by prior restraint?