I agree, SK got some features right.
As for #1, I think the reason for mandatory AY+ account this: If you are a random flyer without any program affiliations, then the app is a great way for AY to get new members into the program. And if you are a regular flyer with ties to another program that occasionally flies AY, then there really is nothing in it for AY to adapt the app for you.
Agree on all the wallet stuff. Pretty surprised it isn't implemented.
There are terminal maps already, but not for all airports.
I'd like to see more manage my booking stuff, like seat selection, onboard service et.c.
Also more stuff added to each airport like lounge access and directions, check-in desk info (location and opening hours would be heaven sent)
The SK app allows for making new bookings and altering existent bookings so AY is way behind in this aspect.