I´ll strat with saying that making Ras all ghoul batman´s master was for me a good think and i prefer this new version of ras than the one from the comis but since that was already done i would start with an origin but in a different way
Film 1
I would use almost the first half to tell bruce´s stories with him travelling the world and meeting an ex vigilantie, the reaper from the year 2 comic but without shouing a costume since he in this version would have been a vigilantie that sowes his face but is killed by thugs, the rest of the film shows batman´s first eforts, including meeting a selina kyle when they fight. The villains would be some criminals that used to work for Falcone but now use different people to use a costume creating a figure named the red hood, in the end he accidentally falls into a pit of accid but the film only ends after batman catches Falcone and Harvey is able to send him to jail, having harvey and a rocky police named James Gordon that is not corruptable and does whatever it takes to stop the mafia.
Film 2:
Black Mask would use Sal Maroni to take the empire of falcone but that ends in a mafia war between Maroni family and the Falcone family, Maroni ends up having to go to the juri but he send a bottle of acid to his fave and when harvey tries to get out there begins to be a shooting and something explodes, burning half of his face and killing everybody that was present eccept for harvey.
Two-face begins to wipe the Falcone and Maroni family one per one and batman catches Black Mask who encounter two-face, and two-face kills him, two-face fakes his oun death and batman leaves him alone for the sake of the old times.
Film 3:
The riddler begins to encounter batman and the joker appears and begins to terrorise the city, making batman and everybody else suxpect of the riddler, there are some more crazy parts, the riddler is used as a decoy by the joker and in the end he is caught and sent to Arkham Azylum too.