I was a young teenager when I first played smash bros so I didn't play in any pro leagues or whatever you're talking about. As far as house rules, it was just me and my brothers so it kind of varied depending on how serious we were. I remember super cheesing the mallet or whatever would knock people off screen. I had many a bruised arm from the trolling I did with that thing.
As nostalgic as I am about SSB, I don't think this will be enough to get me to buy a Wii-U just yet. Maybe when we have a new Zelda (or when my kid gets old enough that I can play with him).