Need to work with #root privileges for a short time in #GNOME?
Don't try to somehow mangle around security systems that prevent you from starting a file manager or gedit as root!
Instead just use the "admin://" "protocol"! E.g. in the file manger (#nautilus) , press Ctrl+L and enter "admin:///root/" to go to the /root dir. You'll need to enter your root password, of course, in a graphical splash screen. Same goes with editing files with gedit then.