Rihanna wanted to be a 'role model' when it was convenient. When she realized that all that "girls look up to me" mess she spoke about on 20/20 didn't sell "Russian Roulette" or Rated R, she stopped using the failed tactic. So, I have no idea what some of this "she doesn't want to be a role model" stuff is coming from.
I think it's best to simply ignore her antics. It's safe to say that Rihanna wants to be "the black Madonna" (lol)
so she's clearly being over the top just for the sake of being over the top with little to no substance to back it up.