I thought Avengers was more entertaining, but it was far from a better movie. I like what Nolan did with these movies, but I don't think he is going for "realistic", just something with a different flavor than the straight forward Avengers.
I agree, the casting of Thalia was wrong, but if they made her hotter, who she was might have been obvious. It was obvious to me in seconds anyway. They basically cast her because she was in Inception, and only a little bit at that, so Nolan is familiar with her.
They should have tried someone like Mia Kunitz for either Cat Woman or Thalia.