3. The Flash is an Addition to a Team that Already Has Someone with Super-Speed
Once again, as comic lovers, we already know two things right off the bat: Flash is faster than Superman Flash's super-speed attributes to him more than running really fast But the fact is, the general audience is going to wonder why Flash is such an instrumental part of the team if they've already got someone who has super-speed. What I'll do is draw a comparison to Joss Whedon's Avengers to this problem: Flash is to the Justice League what Black Widow was to the Avengers. It's always nice to have a helping hand, and because of Natasha's interrogation skills, she had a very pivotal moment in The Avengers with Loki, but for the most part, a lot of people wondered just how in the world she'd help out the super team (I've also heard that a Batman in JL would be like her, as well). And from a tactical standpoint, she did a lot. She got the necessary information out of Loki, reverted Hawkeye back to normal, and ended up closing the portal after Iron Man flew through. However, the Flash isn't necessarily a tactic player. And while I think he could be opened up to the possibility of doing more than Black Widow could, the general audience may be a bit hard pressed to think Barry Allen (or Wally West) is really a valid member of the team if Superman is already "faster than a speeding bullet." Flash is my favorite DC character and I have faith they'll utilize him very well; but this is an issue that's going to have to be faced, whether it's a one-line throw-away, or a scenario that keeps Superman from using his super-speed abilities. I'd rather not have it come down to Flash being Superman's errand boy whenever he can't (or doesn't feel like) use super-speed.