Tywin isn't as evil as Joffrey, Littlefinger, or the guy torturing Theon. And that's just off the top of my head. I'm not saying he isn't ruthless. He's amoral, but not sadistic. Anyways, why doesn't Varys expose Littlefinger to Tywin? Especially after their latest talk? Btw, random question, but if Daenerys returns to Westeros... would Stannis accept her as his Queen? Does he really believe the Iron Throne is his by right? Also, if the Jon theory is true, would Daenerys accept him as her king?