I play until my pokemon get to level 100

Casual I guess. I don't really play online and I don't catch pokemon that are competitively strong. I usually just go for 6 that I like the best.

Casual until I beat the story then I focus on competative.

I breed for abilties and natures,  EV train, and try to get the at least one perfect IV (usually speed).  But trying to make perfect pokes just isn't worth it.

IT IS SUPER WORTH IT!!!!.... trust me

I would say I'm somewhere in between. I take the story mode somewhat seriously but I've never gotten too much into Tournaments or Online Battles. I always seem to suck at battling other people, sometimes I'm good though.

I have been playing the games competitively since gen 4.

Incidentally I was at the Pokemon World Championships a few years ago. I am hoping to participate this year as well to get there, but it is quite tough given I'm no longer in school and am in university now. Plus there's quite a high level of competition now, which is great.

It takes years of practice to get good at competitive pokemon. A lot of it is all about knowing every competitive moveset/stat spread a pokemon can hold. So it helps if you start playing casually to familiarise yourself with pokemon moves/abilities, etc before you move into competitive where you have to predict your opponent's every move throughout the whole match. Its good mind games. Also you can barely call random matchup on the ingame online options competitive. Yes you can get a few guys who run good spreads and have some synergy in their teams, but most people are just casuals. If you truly want to play competitive, you have to go to dedicated competitive battling sites like smogon and challenge people through Wifi.