Stock system is exhaust manifold, cat, front resinator, main muffler and rear resinator. the two resinators are the same type of little muffler thingos.
Having the resinators removed and changed to pipe would increase the noise, probably not much and it wouldn't sound that great. punching holes in your mufflers also increases the noise though (wouldn't recomend it either)
When you can get cheap sports exahust now days for $200 it's not worth playing around with the stock one.

Hey, the thing is a sports muffler on an otherwhise stock system sounds like crap.

So can the stock muffler be replaced with a hotdog without it being over loud?