I've done the general clipboard revamp, and also, since I added
Ctrl-Shift-{C,V} as a new pair of UI actions for copy and paste, I've
also fulfilled the requirement that there should be some method of
non-menu-based pasting that doesn't depend on a middle mouse button or
an Ins key.
I think the list of OS X missing features is now down to details of
the OS X GTK port _itself_, as opposed to structural issues in the
general code base.