One of the reasons Justice League bombed is because the queue situation. I rode it like 4 times, where if the preshow and outdoor queue area was different I would have done it 15 times to be honest. They took away that rule, I did it once and its never really open anymore on any of my visits it seems.
Im also team build a few family coasters. It has stuff for little kids and then its nothing but huge thrills. It needs some middle ground rides, as it is, there no reason to even try and take a kid there until they have been to the OC parks and approve of rides there. By the time they final go, they realize, its far away, the dirtiest and ugliest of Cali parks. Not a good pitch.
Personally instead of building a new coaster, Id legit sell Scream (make 2m bucks, one less ride to maintain, keep the trains for a riddler swap one day, save the plot for another day) add 2 steampunk themed flats by Twisted and the theater, put a show in that theater and no matter what just run it, you gotta offer things first if you want people to do it. A few person carnival mini stunt show like thing nothing big. Plus tear down and redo those tiny bathrooms, food shop and add a little store, All one nice big themed steam punk building housing them. Give them a true themed land. I can dream...