Ah, sorry.
Well, if you care to know, I suppose
...
Short hop is a short jump. Just tapping x/y/up gets you a short hop, versus completely pressing it.
Auto canceling is something that can happen with certain air-attacks. Some aerials will have certain frames in which you can land on the ground and suffer no lag upon landing.
You can try this with Villagers down-air, for example; it's one of the more noticeable ones. Depending on where in the attack you land, you could get no landing lag, or quite a bit.
What I was whining about was Mega Man's Flame Sword is not capable of this. If it could, it would be an excellent "get off'a me!" tool while on the ground. Instead, you're quite vulnerable if you land during it.