Oh, if only....
-Spaceship Earth back to Irons version, now with current new animatronics makes 1 perfect ride
-Living Seas name return where Nemo is only a component of, not the entire basis of, the pavilion
-Universe of Energy, sponsored by Edison or whomever the local FL utility provider is. Explore all forms of energy, keep ride but change out films and remove the corni-ness
-Wonders of Life, presented by 24 Hr Fitness. Reuse Body Wars simulators in a new ride about exercise, keep Cranium Command, bring back interactive stuff to do as well as a Jamba Juice-type bar and healthy foods table service restaurant with gluten free and vegan, etc. options
-Test Track - let's see what they do already but yeah, no more scaffolding and get an attractive facade
-Imagination - of course, return as much to the original as is feasible and reopen upstairs with new stuff
-Mexico - El Rio return with modernized elements
-Germany - new ride in EXISTING building
And that's just a conservative list but I'm willing to be conservative if they'd just tackle some of these.