gnome-terminal shortcuts can also be customized, which is very easy and useful, if you use different applications that ought to have set the same shortcut(s) [applies only to the current active application] for the same/similar function(s).
Example: Closing tabs with Ctrl+w shortcut in
In "gnome-terminal" under "Edit" -▸ "Keyboard Shortcuts" (see screenshots below) you can set your custom shortcuts.
If you use the same setup as shown below, and lets say you have three tabs open, you can simple switch between them with:
Once you activated tab 1/2/3 you can then use Alt+w to close it.