Does Ender's Game need a star?

So do we need a Hollywood superstar as part of Ender's Game?

As far as it goes for us fan boys and girls - No, we'll all be first in line to see Ender's Game when it hits big screens. But who else will be there? What draws people to see a movie, a good trailer, good marketing and YES a big name that we all know.
So recently we've heard a lot of talk about casting for the movie, and its all about the kids. From Orson Scott Card and casting director John Papsidera's comments we should expect a big name there, and that's a good plan don't want some stuck up child actor playing Ender or Bean, think Macaulay Culkin, and you get the idea.
Back to finding a star for Ender's Game, it has to be an adult and they have to feature a fair bit, so what characters can we look at? I have only two suggestions Colonel Graff and Mazer Rackham. So I was thinking who would I like to see and I had what can only be described as divine inspiration, Nathaniel Lees must play Mazer, he fits OSC's description perfectly and he's been in some awesome movies. But I bet you all had to Google him or hit that link to see who he is, so not the kind of star we need.
So its down to Colonel Graff then, and I can't think of a single person, help me! Help Ender's Game who should play Graff and be our Hollywood Superstar?

Ender's Game Movie - Peter the Psychopath

With film news, casting calls and information coming to us frequently about the upcoming Ender's Game movie, I have, like many of you, been excitedly rereading all of my Enderverse books.

Something is troubling me.

According to io9's look at the casting calls for Ender's Game
"Ender's brother is fully a psychopath in this version of the screenplay"

I understand that in the Ender's Game book Peter (Ender's Brother) doesn't come across well. He is a bully, too violent for battle school and also a master manipulator. Going from this to a psychopath for the movie is great, it will add drama and tension and show Ender's altruistic side in sharp contrast to Peter.

But I feel the need to be loyal to the Peter Wiggin of Orson Scott Card's mind and he is not a psychopath. My friend Peter Wiggin defeats the evil Achilles with the help of Bean and then he unites the world under a democratic alliance known as the Free People of Earth.
I want everyone to know this Peter, and as I can't fault the filmmakers for creating a psychopathic brother for our hero, I come to the following conclusion - Everyone NEEDS to read the Shadow series. Peter Wiggin is a major player in this and as you read hopefully you can come to know Peter as well as I do.

Let me know if you agree, or am I the psychopath?
I'll be doing a regular opinion feature so if you have any suggestions on what I should talk about or if there is something specific you'd like my opinion on, hit me up on Twitter