I have unchecked “Show action to permanently delete files and folders” in Thunar preferences. This works as expected in Thunar. However, on the desktop, when right clicking a file or folder the delete option is still present. Is there a way to disable it on the desktop?
The keyword here is permanently hence any deletion goes to the bin.
But what you are looking for is not a custom action but a default action.
They are probably defined in source - so if you want to remove those you most likely have to refactor the source and compile your own version of thunar.
Another thought - since you say desktop - this could be something defined in the xfwm - so first stop is to check the setting for the window manager.
EDIT: not possible.
After much more internet searching and reading, I found that the context menu of the desktop is managed by xfdesktop and not Thunar. Xfdesktop does not respect the option in Thunar to hide “Delete” in the context menu. This was reported as a bug and looks like this option will be added in a later release of xfdesktop.
A work around is to create links on the desktop instead of the actual files. That way if something is deleted on the desktop only the link is deleted.
If my wife could, she would have everything on her computer on her desktop. Links are unfortunately not feasible.
Per @darkcity, in Thunar, it’s just a right-click > Send To > Desktop (create a link).