I think everyone just needs to calm down, if he wants to sound dumb in his posts it's his right to do that.
He sounds dumb in most of his posts, I would never take that away from him, but it's better if he does it without tossing in the hate speech too.
Hate speech and using a slur once are far different things.
You are free to define it however you want, but I don't think that frequency is usually part of the definition.
Hate speech is, outside the law, any communication that disparages a person or a group on the basis of some characteristic such as race, color, ethnicity, gender, sexual orientation, nationality, religion, or other characteristic.[
http://en.wikipedia.org/wiki/Hate_speechhate speech
n
speech disparaging a racial, sexual, or ethnic group or a member of such a group
http://dictionary.reference.com/browse/hate+speech