Question

I thought of this while I was looking for one.

Answer 1

While there is only one of each Pokémon, if the Pokémon faints or the battle is otherwise ended without the Pokémon being caught, it can be encountered again.

So, yes, if you flee from it, you'll see it again.

http://bulbapedia.bulbagarden.net/wiki/N%27s_Pokemon

Answer 2

Yes.

Source: Experience