> I've known a lot of awesome people with intellectual disabilities who have had this label applied to them in the past. It's amazingly hurtful.
Applying it to someone is hurtful. Using this word is not.
It doesn't matter if you substitute "retard" with "r-word" everywhere, nothing will change. Even if you change the name of the condition, you don't change the condition.
If someone wants to be offensive, I'd bet saying "Hey, you're r-word" will do the job just fine. If it was said with an intention to be offensive, it is offensive. And trying to censor certain words doesn't change it. Because words aren't the problem, people are.
I'll quote George Carlin here:
"They're only words. It's the context that counts. It's the user. It's the intention behind the words that makes them good or bad. The words are completely neutral. {...} For instance, you take the word 'nigger.' There is absolutely nothing wrong with the word 'nigger' in and of itself. It's the racist asshole who's using it that you ought to be concerned about." [1]
1. https://www.youtube.com/watch?v=mUvdXxhLPa8#t=50s