I just went through a long list of keyboard shortcuts for Firefox. One that I didn’t see that I would find useful is to press something like ⇧ Shift + ⌘ + C to copy the URL and then paste it into an email or message to send to someone. Does something like this exist?
Choose your own shortcut(s)
=> https://addons.mozilla.org/en-US/firefox/addon/copy-tabs/
Hope it helps.
This looks quite interesting