I agree with much of what you just said, and you certainly belong in the "sensible right" category. The quoted portion here unfortunately doesn't ring true. If all you're doing is filtering out the words n****r and f****t, then people will use other words to convey the same thing. Splitthis will continue calling black people monkeys and dwai will still derail every thread with homophobic one-liners. This is what I meant by Stormfront-lite. You could run that website through a profanity filter but it still gets the same message across.
Sure it's worth a shot. But I don't think it will change many minds about what kind of a website this is, particularly to outsiders.