I don't think there's a danger to being typecast at all if you're Superman, because...and this is not meant as a slight to some of the really impressive actors that have played the character...the role of Superman is one that really any male actor can pull off, as long as they're athletic and within a very wide age range. In other words, because Superman is so straightforward a role, there's a type of invisibility to the actor that plays him.
Well in the strictest sense, you can't be "typecast" as Superman because Superman isn't a "type," he's a very specific character. I guess you could be typecast as a "superhero" but really the only actors I know of who could fall into that category were working in serial days (Kirk Alyn was Blackhawk and Superman, Tom Tyler was the Phantom and Captain Marvel, Kane Richmond was Spy Smasher and Brick Bradford, and so on).
I think the more correct term would be "pigeon-holed." Sean Connery didn't want to be limited to "gentleman spy" roles any more than Flynn enjoyed spending his career in tights and swordfights or Jim Carrey wants to be known as "just a comedian." Conventional wisdom over the years has been that George Reeves' career was torpedoed when audiences saw him only as Superman, and certainly Adam West had a lot of dry years trying to get out of Batman's shadow (and he wore a mask in that role!).
Anyway I think in a way you're arguing the other side; yes there is "a type of invisibility to the actor" who plays Superman, which is the whole complaint in the first place. Put on the costume and it takes you over; it's bigger than you are. An actor has to have a great deal of charisma and star appeal to achieve the same success out of the suit that he does in it. More than that, he needs to find someone willing to take a chance on him.
From a producer's point of view, I certainly see the appeal of casting unknowns. You WANT the character to be bigger than the actor. Donner was wise to fight the pressure to hire a Redford or Reynolds back in 1978. If an A-lister had taken on the role, people wouldn't have said, "Hey that's Superman!"...they would have said, "Hey, look -- Robert Redford in a Superman suit!"
Compare this to, say, Eddie Haskell, who pretty much can only really play Eddie Haskell. Being a Superman actor is a little bit like being an inker: unless you really blow it, nobody notices what it is you do.
Ha! Good point...I rarely single out an inker except for scorn (hi, Vinnie!) so it is a thankless job. But again you're just pointing out how hard it is to be Superman. Do it right and the character gets the credit, screw it up and you're the worst actor ever ("Geez, how awful must a guy be to ruin even Superman!")
Superman as a character is "uncomplicated," a straightforward action hero not unlike the Hercules played by Kevin Sorbo, and as a character, has a wide range of possible interpretations. There's no "right" way to be Superman.
Yes and no. I grant you Sorbo (to use your example) could have acted out the scripts for "The Adventures of Superman" as competently as George Reeves (though I'd argue less charmingly), but we are in a new age now, one where some actors have a say in the script itself. And there definitely ARE wrong ways to *write* Superman. Case in point is the thankfully aborted Burton-Cage project, in which Nick Cage would have played Superman as a dark, haunted "freak" (his word). When a star is big enough, projects get written to fit their "strengths" and personal style even when it means destroying the character and concept the whole thing is based on (see Will Smith in "Wild Wild West").
This is not to say, though, that some people just aren't flat out WRONG to be Superman. My estimation of Justin Timberlake, for instance, was raised enormously when he told some clueless producers that wanted him to be Superman that "Whatever you're smoking, I don't want any."
Dumping Britney was a smart move, too.
Too bad Nick Cage doesn't have the same grasp of reality. Or maybe more to the point, too bad he doesn't value the character more highly than his personal aspirations. Heck, I'd love to play Superman myself, but I'm mature enough to know I'd sink the franchise. (And besides, no one's asking...)
Then again, there is a danger of some actors with stalled careers who fetishize their one role in frightening, Norma Desmond-esque ways. A textbook example would be Richard Hatch from the original BATTLESTAR GALACTICA, whose entire existence is centered on reviving BSG and writing Galactica novels - didn't he actually make a pilot episode with his own money?
Hatch is an odd one. The weird thing is, I stumbled across a Galactica rerun last week and was surprised to see he was a lot better looking than I remembered. He should have been able to do lots of stuff after that show, and if he didn't it's hard to imagine it was because everyone thought of him as "Apollo." How can you be "typecast" by a role in a show that failed? Dirk Benedict seemed to get plenty of work after that. And Lorne Greene became the face of Alpo. :lol: