This proves the point that it's terrible UI though...
"I highly recommend turning on the 'Undo Irradiate' feature on the Therac-25. It lets you undo irradiation settings for a patient for ~5 seconds after you press irradiate. It has saved my patients countless times, not because the UI tricks me into irradiating patients with the wrong settings, but because I realize I want to add one more dose."
Obviously, they've made it easy to send emails (pressing tab then enter) but that means that some folks send them by accident. But that's an acceptable trade, because it doesn't kill people.
Also, as @tomkarlo suggested, use undo_send, that is a life-saver. I set it to max possible- 30 seconds.
Tab -> Ctrl + ]
Shift + Tab -> Ctrl + [
Quote -> Ctrl + Shift + 9
(They are also helpfully annotated in the formatting menu in case you forget.)
Not that I'd ever use them. On my AZERTY keyboard Ctrl + ] translates to Ctrl + Alt + shift + ). I always have to press shift to enter digits so I'm not sure how the last one is even supposed to work in theory.
I also don't seem to have a formatting menu. Are you sure you're not using a Google Labs feature?