here's alison mack saying that the rule was tom wellings doing, not al & miles, the producers.
http://www.mania.com/superman-celebratio...91120.html
as for who's playing who, that was another reason the film got put on hold. they couldn't agree on casting. they wanted people in late 20's so they can have a franchise and are likely to stick about for more films and so they can make them without having an effect on making more batman films, superman films etc, cos if they took bale and that, they'd be playing the character possibly uninterrupted for years.
batman/superman movie would be great, there's many plots from the batman/superman comics that would work brilliantly on screen, they can go straight into it, rather then spent time introducing the characters.
the robin series was thought up by the people that did smallville, nothing to do with the JLA movie. and thankfully that was scrapped.
i'm not saying you're wrong about what their saying, just saying the no tights is tom's rule, they have no control over it, which is why if they are asked, they say no thats all. and just correcting the info about Bart Allen being called impulse as he was impulse originally, then became kid flash and only became flash after his appearance in smallville, which his stint was short lived as he got killed by the Rogues.