Thunar as root

1. Open thunar, then go:
   MENU > Edit > Configure custom actions...
   
   
2. Add a new custom action (+)
   
   
3. Name:
   Open as Root
   
   
4. Command:
   pkexec thunar %f
   
   
5. Icon:
   Select a nice icon
   
   
6. Click on 'Appearance Conditions' tab (top)
   Select (check) 'Directories'
   
   

Done! Now when you right-click on a directory, the 'Open as Root' option is there to click. Any file you edit from the new thunar window will be edited as root.