Thanks for the suggestions, Boze!
On point 1- you might not realise you can hit the X button to change the type of object sorting? The reason it changes is that it's set to 'by room type' so detects the objects for the room you're currently in. Walls don't have a room designation, which is why it changes. If you hit X that should list all objects A-Z and won't change unless you choose to.