I want Batman to have Jason Todd as his partner, with Dick and Barbara playing a bit/background parts. Establish Todd as the likeable but headstrong 2nd Robin. A Robin that goes too far, using his position and training to get unneeded revenge on criminals and doing stupid things he think are right. Bruce, unable to change his own mind or accept that things can be done differently, works the entire movie to reign him in. The movie works hard at making the audience feel sorry for Jason and rooting for Bruce to help redeem/save him. Jason comes through in the end, realizing his faults, saves the day, gets forgiveness and acceptance from Bruce. Movie one's last scene is Todd's abduction. That's a cliffhanger that could keep people on edge.
Movie two opens with Todd's brutal beating and then death. Fading in and out of consciousness as the opening credits play. He dies and is gone for the whole movie. Bruce vs Joker or whatever, I dont care. I just want that soul-sucking opener of Jason's death haunting everything that happens afterward. I want a haggard Bruce pushed to the edge for revenge. Batman v Superman had that, but it was empty and unearned, a big fault that most people thought detracted from the movie. Give Bruce a better reason, push him past the edge, make audiences rethink just how much they want Bruce to get that revenge. Flash at how violent Jason was until Bruce helped him. Toward the end he is stopped by Barb and Dick, who help turn him good again, realizing that he doesnt need to avenge Jason, he needs to remember and learn from what happened.
Movie three is the Red Hood and Tim Drake coming in as the replacement. I want the whole damn Bat family there. Bruce, Dick, Barbara, Tim, all working to take down Todd, the villain that knows Bruce better than any others, the villain that unites all the others (Penguin, Two-Face, Riddler, Solomon Grundy, Ivy, everyone) to take him down.
We have had a dozen movies about Batman and his arcs. Use the new trilogy to help establish and create arcs for a supporting cast just as good but never as highlighted. Playing up that team aspect and doing it well would establish this series as much more and in a big contrast from everything that has come before.