This is unmaintained, so it may not work with the latest ubuntu, but it is an extension to the default ubuntu file manager that does some of what you want
As for your title question, unfortunately ubuntu/gnome don’t seem to make this easy. On some DEs you can just right click and go find the shortcut properties sorta like on windows. Others have noted some good reasons why GUI apps shouldn’t run as root, but you’re right that sometimes it’s necessary, or simply the easiest/most expedient way to do things.
You can accomplish what you ask using a little shell script though, which you could bind to a keyboard shortcut or something. I may elaborate further but basically:
readlink /proc/“$( xprop _NET_WM_PID | sed ‘s/_NET_WM_PID(CARDINAL) = //’)”/exe
and then clicking on the window you want to ID will attempt to identify the binary it’s running. then you could either display it in a popup using zenity, or write it directly to the clipboard using xclip (or wl-copy I think for wayland distros)
I really like setting up little shortcut scripts like this with zenity for user input, and usually the notification tray or clipboard for output