1. Do we have a responsibility to play clean music if we're blasting it in our car?
I typically dislike 'blasting' music in cars because I dislike listening to other people's music. And of course, if you're not 'blasting' it and it's just your car which can hear it, then you can play anything you like.
2. What do you think about artists using the n word? Is it okay for us to listen to them?
It is DEFINITELY okay >

I am against political correctness and whatnot, and if this is a term that we have gotten used to, then by all means it is now part of our language, even if the language is not
desirable. And music should reflect that.
3. Should we listen to clean music? Is it fair to censor what the artists originally intended for their work?
If the artists don't mind themselves being censored, then it is 'fair' I guess - but that is a strange word to use. I understand how some parents might not want their children to listen to swear words etc., but sooner or later they will have to face them and come on - in a hundred years' time, the swear words we know today will probably cease to be swear words, and there will be newer, meaner ones invented.