Me and Clark may have been around for three quarters of a century, but a lot of our readers haven't, so even retelling stories that have already been told isn't necessarily a bad idea.
That parallels what I mentioned above. Can you push someone right up to the line he won't cross? Who blinks first, you or him? It's an interesting question with Batman but you can only tell that story so many times. Someone who's new to comics can go right to the best arc and read how Batman is tempted. Someone who's read the best and the worst is going to be bored the next time that question gets raised. It'd be interesting only if someone else is asked that question.
There's only two ways around this sort of thing I can think of and franchise suits wouldn't go for either of 'em.
Idea #1: let the world go on. Heroes age and die. New guy takes up the cape. There hero is dead! Long live the hero! Yeah, characters who are expressly immortal get around that. But I doubt that the powers that be would go for it.
Idea #2: Accept that there will be a new era and put a strong editor in charge to shape it. At the beginning of each era it's a whole new playing field, anything can happen. Plot out important story arcs, play damn hard, play for keeps. Plays out to a fitting conclusion. Wrap it up, hand off to the next major editor. This also provides the advantage that only the elements that are decent will be brought forward. Harley Quinn was an invention of the Animated Series but was such a great character that she was brought into the comics. It's hard to imagine the Joker without her. A new editor might want to make his run of Batman as realistic as possible so does away with gimmick villains, explicit use of magic, mutants, and crazy scifi stuff that doesn't exist in the here and now. The editor following that might say ok, we've done enough realism, let's be more tolerant of the weird and paranormal. Mad science does work. The dead can be brought back to life. But it's a conscious decision to include these ideas and you don't end up with a thematic mishmash.
I mean this is what they're essentially doing with most reboots. The recent batch of Godzilla movies ran with the premise of "There was only one Godzilla movie, the original, and these are the direct sequels." The last Superman movie ignored all the crappy sequels. The two Hulk films were so bad, Avengers pretends neither of them happened. The third and fourth Batman movies were so awful that the franchise appeared dead. Batman Begins is the first time I've ever heard the phrase "reboot" used.
One other thought about setting an era: you get that beginning, middle, and end. I think stories need good endings. It might not be the final story to tell with the characters but at least there's the hope you won't start telling a new story unless it's one worth telling. The problem with open-ended franchises is that they never end with dignity, they just tend to run on and on until they age into depressing shadows of their former glory and the end isn't a high note, it's like holding a pillow over the face of a comatose friend because you know he'd never have wanted to end up like this. It's mercy, isn't it?