NRHH: Why r people so up in arms over saying "f^ggot", "gay", and "retard", but just wave off the "n-word"?

Okay, let me explain. The "N" word is spelled and pronounced with er,while it's derivative "*****" is pronounced and spelled differently and also has a completely different meaning. By changing and manipulating the word, it is no longer offensive. I personally don't give a **** if a white person says *****, as long as they don't mean to offend. Gay is used as a synonym of bad, which is an insult and I don't even have to explain the other two, which is why they're offensive. Also, it's not as offensive if a black person says the N word or a if a gay person says the F word.