It will be a great enhancement to allow create groups of Personalized Actions. 

It will provide a way to group some action and keep organized the action list.

For example: A user can create a group called MODIFY IMAGE and create inside some actions like "rotate left", "rotate right", "scale image", "convert to png", etc. and asign the group to all image files pattern.

Another example: A group called ROOT ACTIONS and inside "open as root", "edit as root", "run as root (gksu)", etc.

This grups could provide a more efficient and useful way to manage actions in Thunar.

thanks for your work! ;)