Hi!
I think it would be cool to have an option for layers to enable a parent object for them. This option will create a helper object with outlines representation along the bounding box of the whole layer content. All objects in the layer and nested layers will then follow the transforms of the parent object. Then there is no need to manually create a parent object and link all layer content objects to that one. If the layers contain objects, that are already arranged in hierarchies, the layer parent only affects the root (upper parent) of those structures and won't disturb the internal parenting.
Thank you and greetings!