Remove any remnants of Rapids, Skylink or Mine Ride (perhaps sans the Mine Ride station building) & regrade the land to a nice hilly space.
Put a clear, clean path in that connects Rocky Hollow and the pathway from Main Street at ground level (this also means cleaning up the clusterf*ck that is the Giant Drop elevated pathways and adding in level railway crossings, which would help add atmosphere for that space.)
Move Model T-Ford Cars there. Have them going up and down through the hilly space.
Refurb the old Big Brother outlet to a great F&B Gold Rush space. If you do it properly, it'd be a fantastic space to have lunch or a beer (views of Log Ride, Giant Drop, T-Fords, Buzzsaw, great atmosphere.)
Move some of the Corroboree animals down to new Gold Rush Space i.e. abandoned brick building is really a snake exhibit. Will help make the overall space more full, complete and family friendly.
Long-term, add a Gerstlauer family spinning mouse ride that could dip up and down through the area and be a worthy Mine Ride successor.
To complete the area, add a windseeker in or another small, family friendly attraction.
To me, the idea of having "Gold Rush, Rocky Hollow & Corroboree" as three "worlds" (not to mention Gold Rush is shoe-horned in there somehow) is making life hard for yourself. To me, they're all a rustic, Australian theme. I mean yeah, give them names, whatever, just get on making it feel like one big consistent space and make it feel like a nice space to be in (which isn't hard, Corroboree as it stands is already great, ParkChat live be damned.)
For the park to heal and for the general public to move forward in the conversation of Dreamworld, it needs to really get on removing Rapids AS SOON AS POSSIBLE in my mind. I'd be transparent about what they're doing with the land too, so that when the bulldozers come, the message people are getting is "okay, they're dealing with the space, they're putting in x & y new things, I look forward to seeing what comes" not "oh, they're getting rid of the accident and covering their tracks" which is what folks will default to if they're not given something else IMO.