Well, Hazel, while I understand that it's certainly tricky to do with FoLCs you don't know (and personally I wouldn't do it for reasons you stated above), I really want to clarify that I didn't take offense with Wendy's... um... interesting choices for me.
I was laughing too hard for that.
Seriously, I think that authors know that when they include someone into a humorous cameo, they can give evil roles to people they know will not get upset.
When two people are friends and very much used to teasing each other constantly, there's no risk.
Kaethel