I'm mostly working by accepting what amounts to received wisdom from bloggers, who say that "idiot" and "moron" (and for that matter "retarded") are not okay. I don't desperately want any of these words, and the above alternatives exist without (as far as I can tell) offending the bloggers or the people they speak for, so I invest a minor effort in the vocab shift. I'm less willing to do this sort of thing when there is no viable alternative word with the right features.

I use "crazy" and "insane" sometimes, but I have been encouraging the preexisting shift in their meanings towards a not-necessarily-negative meaning of "extreme" (e.g. "this ice cream is insanely yummy!")