I think it's going to be hard to write a JL movie because the powers of the characters are so unbalanced.
It's the Superman problem.
In that Batman vs Superman comic, Superman had to get hit with a nuke and then go up against Batman in a robot suit for Batman to have a chance.
Oh... there's more!
How the $%^& did Batman survive this attack by Superman?
Superman / Batman Issue # 39
A hypnotized Superman is ordered by Darkseid's sorcerer to "KILL" Batman. He then flies towards Batman with super-human speed that basically plows through an alien building, cutting it in half, as he tears the ground below him. Superman then throws a powerful vicious right punch to Batman who manages to somehow have super-human reflexes himself to avoid it. Superman's punch instead hits a building and demolishes it like styrofoam. Explanation for Batman's super-human reflex to avoid getting his head blown off? According to Batman in the book "Superman just seemed slow".
As Superman's initial blow obliterates said building from the previous page, he continues to lend chase to Batman, and using his super-human speed again, appears right in front of the surprised Dark Knight (and he thought Superman "seemed slow" on the page before), this time, Superman connects with a direct punch to Batman's sternum. "BAM" indeed.
I don't know about you, but a direct hit like that from Superman should have blown a hole into Batman's torso like it was made of styrofoam just like the previous building he demolished. Yet, Batman (surprise-surprise) is shown having survived that direct hit from Superman with only some shattered ribs and "possibly a lung". More surprisingly, Batman still manages to stand up from his painful injuries.
Not seen on this page, but on the following issue (#40): Batman is later saved from being literally murdered by Superman, by turning invisible thanks to a special guest characternamed Bekka (lucky bastard).
One issue later...
Superman / Batman Issue # 41
It is later explained that Batman survived Superman's direct punch because "Superman was holding back".
Just going to skip the whole "Superman seemed slow" and just go straight to him throwing the punch -- So if Superman was "holding back" when he punched Batman, why the heck did his 1st punched (the one that whiffed) was so powerful it demolished an entire building? Guess Superman was NOT "holding back" on that one? But then he later decides to "hold back" once he threw out his 2nd punch?
Batman's pretty much god-like invincible in the comicbooks nowadays. Even more so than any super hero in the world including Superman. It's ironically funny.
This is why "Superman vs Batman" stories never work.
Tip to WB: a JLA movie should really stay away from this kind of horrible, non-sensical writing.