regarding the bookmarks, there is the command "Delete Without Children":

This command will delete a selected bookmark, but will keep the subordinate children bookmarks of the deleted parent bookmark (unfortunately, the command does not work at the moment if you select more than one parent bookmark).
My situation however is the other way round: I often have documents with lots of (meaningless) children bookmarks:

Here, I would like to delete only the children bookmarks and preserve the parent bookmarks.
Is there a way to do this?
Regards
David