Using it for a good natured joke or even self deprecating humor can have a positive effect on it.

I really don't think you're gonna have many people agreeing with you on this one.. it's hard to say a joke is good natured when it uses a word that defines a group of people as an insult. The context isn't going to matter to someone with a disability who's been called a retard maliciously. To use the same example as before, there are plenty of "good natured" people that use the hard R for humor and it pretty much is never gonna land. Or when a gay person hears a straight person say something is gay, they don't really care how many gay friends you have.

Just to be clear I'm not trying to tell you not to use it. Like I said before, I'm an asshole and use it with my friends too. But I realize this makes me an asshole, and instead of trying to spread my asshole around (phrasing..) and convince the people I'm offending that they shouldn't be offended, I keep it to my circle of asshole friends and accept it when people tell me I'm being an asshole.

As someone who enjoys language, you understand that it changes over time. The time period where "retard" is a word that can be thrown around on a TV show without repercussion is coming to an end, just like the time period where calling gay people fags and black people negro or worse came to an end before. Language is not static, we can try to pretend it is but that's just not how it works.

Hope this didn't come off as a rant or anything. Just trying to give my understanding, one retard to another.