Maybe it wouldn't be too obtrusive if they showed the number briefly inside the enemy health bar, but I wouldn't want them escaping out into the world and floating away.

Highly doubt it.

Wouldn't mind it as an option. Most people, of course, are gonna think it's a little too gamey for TES, but I'd like to be able to turn something like that on every now and then to see how much damage I'm really doing.

I'd like it as an option so I can turn it on if I want to get a better feel for my weapons.