Question: This is not just gnome terminal, but pretty much all gnome windows: When you hold the "alt" key, you can press the first letter of one of the menu items. This will let you scroll that menu without clicking on it directly.

This is okay on any other window, like say Firefox, but on gnome terminal, it steals the keys I use for emacs!! There is very little chance of me learning a new set key combinations if I can avoid.

If I can't isolate this just to gnome terminal, I'm fine with that.

Answer: 
Edit > Keyboard Shortcuts..., and uncheck "Enable menu access keys".
In Ubuntu 16.04, go to System Settings -> Keyboard -> Shortcuts -> Launchers, and clear the *Key to show the HUD* (or change it to another key)