There are rumors that Dean and Teri really were involved at some point during the making of the show. She was married for most of its run, so who knows if its true or not. If it was they did not want it getting out. There is a segment of L&C fandom who are stilling hoping they end up together in real life.
I do not agree with the criticism Cain got as Superman. The idea the show had was that Clark was his real personality. So as Superman he was aloof and unconformable with the attention he got. He wanted to do good but not be a celebrity. It reminded me how many actors are uncomfortable when they have to do interviews and public appearances. But are completely different when performing. Hence the idea of him being a working man with powers. Like real life heroes, cops and soliders, who down play the praise they get by saying they were just doing their job.