Ooh, Willem Dafoe would be interesting indeed. I always loved the suggestion of Crispin Glover as well, but Dafoe would definitely bring more intensity.
I think Affleck could work a lot better with better writing and direction, but I would definitely agree that someone better could be found to take the role. I’m not sure Jake Gyllenhaal would work that well, as he’s rumoured to be in consideration for the role. He’s a good actor, but I don’t think he’s the right fit. I’d actually bet that an unknown (or at least relatively unknown) is probably the best option that’s hiding out there somewhere, like Gal Gadot for WW or Chris Reeve for Superman.
RE: Why the Marvel Cinematic Universe Works... and the DC Cinematic Universe Does Not