How can you lay claim to a god damn word. Nigga was jacked from the racist nigger, probably as parody. Than its thrown into the mainstream vernacular by every rap artist on the radio. If the word has any meaning, its probably gone from over use. Just like fuck. Fuck used to be off limits. Now everyone's fucking everything. A word can't be used left and right in pop culture and be off limits to someone. The cats outta the bag at this point. The context is what's important.
When it comes to wordplay, some people struggle and fall back on dirty slang. For others, its just a part of their everyday language. In a social context, the word nigga does not come up in white circles. But in hip hop, the word is dropped so damn much that if you memorize the flows of your favorite artists, it's bound to cross over into your flow if you're just flippin off the top of your head. It's like osmosis. There ain't no excuses here, just truth.