I basically would want them to be as stealth as possible about Coin. People might not (or probably wouldn't) figure out right away she's evil, but would know she's a really big player in the story. Not some cold authority that you see in the control room a few times in MJ1. By getting PSH for head gamemaker you're already letting people know that the new gamemaker will be more important than the old one who was played by Wes Bentley. You don't get PSH to play a role like the one Wes Bentley had, you get him to play someone more important. And I don't mind that they did that, I think PSH is perfect for the role. But I want more "stealth mode" with Coin. Just so it's not Meryl Streep (I seem to have the biggest problem with her
), but someone less big (when it comes to her acting status and mainstream-ness. I mean, she's a symbol for great acting) and less imposing (I think she can "steal" the screen from anyone, that's what I mean by imposing). Like I said, Tilda would already work. For general audience she's not so well known (I just remember my friend's face when I mentioned her and I had to mention Narnia to her to make her remember who Tilda is) and she's still a great actor. Basically, all of this makes some difference for general movie going audience who hasn't read the books. For any of us it's not so important because we already know how big Coin is gonna be.
Also, I agree on not getting someone who seen as playing mostly evil roles.
Edit: Btw, I don't think the absolutely have to do this. Or if they don't do what I suggest that the movie will be ruined. I just thought it might be nice if they go that way. If they don't, like I said, for me it doesn't matter, I know who Coin is anyway.