They need to replace Vortex with a inverted BM and call it the Bat. Don't touch the Beast, unless they can replace the trains with more comfortable ones. (Hmmm...have GCI retrack so they'll allow KI to run their unique trains on it the Beast?) New trains and retracking on the Racers so they have one go backwards (Surely one of the manufacturers can build a train that seats people backwards?).
Build a spinning coaster somewhere in Coney Island. See if itamin could build a double ferris wheel with secure seating (I'm thinking horse collar type--over the shoulder restraints.), that would allow it to go around fast and let certain seats flip upside down. Put where the Flight Commander use to be. Then put in a screaming swing.
After they remove the SOB, replace it with a Maverick clone. Move the BLSC over there and re name and re theme it. Tear out the Crypt, and put the antique cars back in. Relocate lots of trees and then visit Dollyworld to see how to theme a 'frontier area'--including the food. Build a themed log flume that interacts with Diamond Back and has tunnels.
Later on down the road, let RMC build an SOB like Outlaw run in the woods behind the racers. Replace Flight Deck with a wing rider.
After that, replace FireHawk with a BM flier. Retheme area to a 'Hanger 52 theme'. Lots of glowing aliens, maybe add a dark ride if they can afford it after all this.
As a longtime Kings Island fan who rode the racers at the age of five the year they opened, this would would be my realistic 5 to 10yr plan to revitalize KI to what it should be, while honoring it's rich past traditions.