roberto carlos is a NAME only. the best performance we have seen out of the leftback position was by junior in the costa rica match. i like roberto carlos, because i think he's an exciting and flashy player who can do some crazy things on the field, but junior is a much better fit for this team.
junior is more of a team player, whereas roberto carlos just loves to run around with the ball by himself. roberto carlos has been TERRIBLE crossing the ball, and he has been shooting way to much -- and his shots are awful. did you see the semifinal against turkey? i think roberto carlos had more shots than ronaldo and edilson combined.
to answer your questions: no, he has not played very well in this world cup; i don't know if he deserved to be picked in the top 11 because i haven't been watching any of the games not involving england or brazil, but it seems to me roberto carlos was selected because he's one of the biggest names on the best team in the tournament; his best game so far was probably the second game, against china, when he scored a beautful free kick after 15 minutes.