here is config to always have root with homunculus file manager.

just edit the homunculus.desktop file in /usr/share/applications/hildon

Make sure you have rootsh installed.

You just need to edit the Exec line as below.

[Desktop Entry]
Encoding=UTF-8
Version=1.0
Type=Application
Name=Homunculus File Manager
Exec=/bin/busybox sh -c 'echo homunculus | root'
Icon=tasklaunch_file_manager

WARNING doing this will alow homunculus file manager to edit/delete system files, do so only if you know what you are doing.