file system partition
u mean "/"? I think for root (/) file system,root must be only give write access.a local user must be limited to his ~/ directory.the root permission 755 is perfectly fine.u can have access to /tmp fully.the root permission system that protects the system.use nautilus as root by making a launcher is /usr/share/applications/root-nautilus.desktop containing the details and the command "gksudo nautilus --browser".use alacarte gui editor to achieve that.it is in preferences>menu editor.