If they're smart, they won't just turn it all into Tiana: the happy ride. And I don't believe that simply because it's a princess ride that this will be inevitable. Not only is that not true to the film, which does have a conflict (yeah, the ride apparently takes place after the film, which is dumb, but so many sequels recycle the first story's plot anyway, so they can have their cake and eat it too), but I don't envision them giving up what was at opening the largest flume drop in the world. If people are going to be anxious anyway, as the drop will still exist, they might as well play into it. If it's not against established movie canon and it's not an over the top horrorshow like the original Snow White rides, I really think most people will be fine. The youngest and most likely to be scared will be kept off the ride by the height requirement anyway.
The top level of the show building, if they really want to minimize new content, can be Naveen and Tiana going back to the woods and reminiscing about their movie experiences, keeping most of what's there in the process, while talking about their party plans occasionally.
Then, on the lower level, where Brer Rabbit got caught originally, Tiana and Naveen are changed back into frogs, Facilier having finally caught up with them after all the "yay party!" setup. Perhaps he also does something that makes it difficult for them to get out of this situation. Cue "Friends on the Other Side" as they approach and go up the lift, with the voodoo spirits chasing after both the characters and us, the riders! At some point, after the drop and prior to the finale scene, they're changed back into Humans, having survived and somehow dealt with Facilier. Then, for the finale, there's the grand celebration on the showboat and the musical show, etc.
To me, that makes sense; they can't go full Little-Mermaid-no-measurable-conflict: the ride! if they keep the most important parts of the ride track, and it would be to their detriment to try and do so.
Oops! Just fixed it.
