Are you really that worried whether or not people will take your post as a joke or an insult? If they do feel insulted, then clarify afterward that you didn't mean it in that sense. o_o?
The way I see it, either you get rid of all the formatting (great for people who didn't want to see them in the first place) and risk whatever misunderstanding that may come out of italics and bold in your post, or just accept everything.
If people disable everything, I should hope they're conscious of the fact what they see isn't the same as others, but that's fine because that's what they wanted in the first place. In that sense, yes, I think it's effective for its purpose.
I don't deny that it'd be interesting if you could personalize it more (choose to omit and keep whatever you want), though. I know many people would only want to get rid of the font color and size.
/2cents