Very old idea that I could have used in many occasions: a "Deleters" field: who can delete this document? It would be the solution to have real owner control over Deferred mail (see what's hot at the right :-).
Similar fields: NonReaders (Richard Schwartz), and one could think of ...
Fields with typ Readers, Authors and Names can be set as "use adress dialog for choices" in Designer.
I would like an additional checkbox to this setting that will restrict users to only select people, (i.e not groups)
e.g The addressdialog should show only a view containg people.