Add policy to Polkit
From the Ubuntu bug
http://www.webupd8.org/2015/03/how-to-run-gedit-and-nautilus-as-root.html
Add the file https://raw.githubusercontent.com/hotice/webupd8/master/org.gnome.nautilus.policy to /usr/share/polkit-1/actions/
So the user can start a nautilus session with superuser privileges to edit files outside the home directory using 'pkexec nautilus'.
Alternatively, does the Nautilus team just want people to use admin://
rather than pkexec
?