No, if Singer didn't want him to play it a certain way then he wouldn't have, he was just doing his job to a T.
He did a great job with his performance, I'm sure he gave a ****, how much would it have benefited him to have boned up on the comic book Lex anyway when the Lex he was playing was pretty much supposed to be a "darker" Gene Hackman Luthor hell bent on revenge against Superman for his jail time - virtually nothing to do with the Post Crisis Lex we all love to begin with? And the script for the movie, in fact, even much of the film isn't a
bad movie, it's just not a great
Superman movie. It is well made and
the dialogue is better than anything Goyer wrote for MOS, the emotional beats are good, and while I prefer MOS to SR, that's all I have to say about that.
My only problems with SR, really, are the super kid and the lack of Superman fighting anything/Superman "action", the little bits they had him do in it I liked and thought were cool.