I think that Spensa will either end up in the cavern in Detritus that has the symbols she saw in the delver maze and near the nowhere portal or on planet ReDawn (Alanik’s home planet)
No, because FM temporarily left Skyward flight then rejoined. FM was a scout at the end of Skyward and Jorgen was assigned to Riptide flight. Jorgen’s flight number remained 01 because he is flight leader.
Alanik was using her cytonic powers to hyperjump. She was not in possession of a hyperdrive. She instructed Spensa to go in her place as she knew she wouldn’t be able to.
Brandon Sanderson did say that the delvers are a new thing he created with Skyward. Jason spent some time in the nowhere in DE but sensed no delvers. This is why.