Box1: No -
Policies cannot be recovered.
Box2: Soft delete is enabled by default on all key vaults. You cannot add a new key named Item1 because an object named Item1 exists in a soft-deleted state.
Box3: Soft delete is now enabled by default on all key vaults so you can recover Item2.
Reference:
https://docs.microsoft.com/en-us/azure/key-vault/general/soft-delete-overview
https://docs.microsoft.com/en-us/azure/key-vault/general/soft-delete-change