Okay...I'll cut down on the "no"s...but can I PLEASE use them every now and again? lol
Anyways, a subseeder is a pokemon that uses substitute and leech seed to annoy the foe. Secptile is one of the most common subseeders with its tremendous speed, as is jumpluff. Roar and whirlwing can break through subs though, which can help get rid of them...but they are extremely annoying to fight if you aren't prepared.
EVs...any good trainer EV trains their pokemon. There are several guides online, including one in a sticky of this forum, so I suggest you look.
Sweepers don't necessarily end battles fast, they are pokemon with high speed and either high special attack (special sweepers), high attack (physical sweepers), or both (mixed sweepers). They are the pokemon that use direct damge moves to harm your foe, but walls often stop them...suck as blissey, who walls special attacks.
Back to subseeders, I'd use the subseeding set for Scepy...it has worked the best, probably why it is standard.