Is it possible, to assign a label or a status to a folder AND all subfolders / documents in one step?
Yes, in the sense that you can apply a label or status to all the documents/folders you have selected at once. To select more than one item in the binder, hold Ctrl and click on each item, or select the first item and whilst holding shift key, select the last item. All of the intermediate items will be selected. Then just right click anywhere in your selection and choose to add status and or label. All of the selection will be done in one.