Never. I've only received 2 WPs. All with the first couple hours of being accepted for shading Britney (the "new member" excitement got the best of me). She's one of my faves too.
I also don't post very often, or at-least not as much as many other members. I tend to observe more.
I don't think I've ever received a warning point. But if I did, I'm sure it would be when "ARTPOP" is released or if Ke$ha releases another single off "Warrior".