Smeargle can learn any move in the game permanently, yes. It can also copy moves over WiFi, yes. Of course, it loses the move after the battle is over, as WiFi doesn't make any changes to your team, so the only way to copy a move permanently is ingame.
Also, Smeargle fails in competitive battles. He can learn any move, sure, but it's not gonna do much coming off of a 40 Base Attack. And with 75 Base Speed, he'll be dead before he can do anything not named Ice Shard, Extremespeed, or Quick Attack. Smeargle can make a decent Spore/ Baton Passer, though.
I have an Idea.... EV TRAIN THE SMEARGLE x_x
Clever yes?
Anyway, I would laugh so hard at a Smeargle with...
Blast Burn
Hydro Cannon
Frenzy Plant
Hyper Beam
Yes... that would be powerfull, but after very move it would have to recharge, not to mention each one of those moves only has 5pp but anyway, It would be cool... sort of...
And
Amzo, I want to see you eating a sombrero... that would be amusing.... and also Amzo, your name reminds me of my nickname
Ramzo is my nickname...
Amzo get where Im coming from? Lol.