Let me break it down.
If you get offended by the word "nigga," then don't allow nobody (even if they are your same race) ever call you that. Simple as that. You don't get no "free" pass to say a word just because of your race. There are no exceptions.
Also, saying "nigga" is like the "cool" thing to do. I hear Phillipinos and Latinos use it all the time. Does it bother me? No. Do I feel like they shouldn't be using it? Yes. African-Americans call me "essay" at times and it offends me, so I know how an African-American feels. I simply do not tolerate such a word... even if the person knows me. If you don't know me and call me an "essay," I'll simply ignore you because I take it as lack of respect. How am I not gonna know an Asian guy, walk up to him, and say, "What's up, Chong?" (like I've been knowing him for years) and expect a respectful answer? I know it shouldn't bother me being called an "essay" by a stranger because there's far more important issues going on in the world, but I feel it's a racist remark because not all of us call ourselves "essays." Especially not me because being "cool" isn't one of my life's struggles. You can't just be stereotypical and assume all Cubans sell cocaine just because you saw Scarface. You see what I'm trying to say? Would they be calling me "essay" if I was White? They'd probably say, "White boy." Would they call me an "essay" if I were Asian? No.
Also, using a word that was once used to put your people down and turning it into something "cool" is not okay. It should be removed completely because turning it into something "cool" to "prove" that it doesn't hurt you means it'll remain in the generations' to come vocabulary.