Considering he musical is very loosely based on the books, I imagine they'll pick and choose just pieces to build a new story on (Glinda and Elphaba's friendship is like 2 chapters in the book).
One of the things about outdoor rides is they do add kinetic energy to the land - especially at Berk where there's the coaster zipping by and the flyers appearing over the buildings. One of the things people complain about Galaxy's Edge is it feels empty
MK is closer t0 85k (they actually hit 80k once). And tell me what theme park worries about comfortable capacity? Certainly not Disney or Universal. They are looking for $$$
As the park expands many of those issues will disappear (for example there will be a who;e new land - or 2 - between Stardust and Potter). Like when the MK opened and the corner by TLT and the castle had a huge blank cement wall which is now hidden by trees, shrubbery and a berm.
Except it has more animatronics than Disney puts in theirs nowadays (plus I feel Victoria's movements were way more realistic than Tiana's flailing about - lol)
It was never just a pass holder preview. Right off the bat there were military, hotel guests and visa card holders. And they didn't even sell all of those. Just because they said they had a block of tickets reserved for pass holders didn't mean all the tickets were. Capacity is still capped at...