I'm sure the Gotham thing is because of fox not Dc themselves.
I'm pretty sure that the Gotham thing is because DC doesn't want it interfering with their precious Batman VS Superman movie.
Same thing for their TV universe.
While Marvel has accepted and integrated the TV and movie universes via Agents Of Shield and Captain America: The Winter Soldier, DC is being a bunch of douche-bags by not connecting the 2 mediums.
I see no reason as to why Stephen Amell can't also do the part of Green Arrow in the new Batman VS Superman movie, as he's done a great job on the show.
It baffles me as much as DC not choosing someone like Michael Resenbaum (Smallville) to play the role of Lex Luther, over some herp derp like Jesse Eisenberg.
I'm not saying that Eisenberg couldn't do a great job in the role, but I wonder why they didn't even consider Rosenbaum.
An the whole thing of saving one from Ra's has been done before Bruce did it to save Damian, his son from his grandpa from taking over Damian's body because the pit's effects weren't lasting very long. Although the setting was different the ultimate goal was the same to stop the league from hunting down Damian. Ra's didn't take Bruce's deal because his body was already old.
In the alternate timeline of the Flashpoint, Ra's al Ghul is 1 of the H.I.V.E. council members.
I don't see how the Lazarus Pits or Ra's is only a Batman thing, given that H.I.V.E is responsible for turning Caitlin Snow into Killer Frost.
As for the Lazarus Pits, others have also discovered the existence of Lazarus Pits, such as characters like the second Black Canary (Dinah Laurel Lance), Lady Shiva, the Joker, Kobra, Nora Fries, King Snake, Duela Dent, Wonder Woman, and Bane.
The Lazarus Pit has been used various times such as when Black Adam used it to revive Isis, in the Himalayas, and in an alternate timeline where the original members of the JLA had been killed.
Superman and Batman used the Pit to resurrect Green Lantern, the Flash, Aquaman, and the Martian Manhunter using their skeletons.
Again, I fail to see where the Lazarus Pit is specific to Batman.