How to edit the "shutdown" menu in Xfce4?

Question

linux

Good afternoon!
Please tell me how to remove the menu items "Shutdown, restart, etc." from the shutdown menu? Or make them inactive. You need to leave only "Exit".
I started tinkering with LTSP on Ubuntu 16.04 server + Xubuntu desktop - if a user (not an admin) tries to reboot or shut down the server from a thin client, then of course he gets a request for a root password. If you do not enter it or enter it incorrectly, the system simply throws it out and re-displays the login window.
Those. it is not clear whether the user ended the session or stupidly threw it away. To save the nerves of newly minted ubuntovodov ))))))) at work, I want to remove the buttons that they do not need :)
And maybe there is one more nuance - the shutdown button on the login page correctly turns off the NUC (thin client), and the shutdown button when working in the system tries to shut down the entire server. How can these actions be changed? Those. turn off the NUC from the system?

Answer 1

make it easier. add system actions to the panel. leave one thing - the end of the session.
through menulibre, remove the logout from the standard menu and that's it ... I did it.
need to end the session? here is the button. and all.

Answer 2

Maybe it's easier to configure this very output to a physical shutdown button?
And explain to users that now you can finally turn off exactly the way they usually try at first;)