Here's a way to implement Thunar custom actions using rxvt unicode (urxvt) but could be adapted to other terminal emulators. It has been used to provide:
- Terminal here
- root terminal here
- vi
- vi as root
Optionally it allows the custom action to set background colour and a fullscreen window.
Caveats: the mechanism is "proof of concept" and not widely tested at the time of posting. It is designed for use on a workstation with a single user.
The key to...