1. Wrong
2. Wrong
3. Preferably enough to taxi to the gate when you land, but if you flameout while touching down, that's fine... although you start getting into the "hazardous and reckless" catch all reg if you do that too often.
Reference #3, I disagree. I think you should always have enough fuel to make it to the gate. Its really a pain in the a$$ to have to wait for a tug!!