Depends on where you play really.. on many of the proddy shards you'll always have a bunch such as you described. For the most part though, they're usually balanced out with a good number of mature, RP evil PK's which make the game exciting.

While there are certainly ALOT of immature, foul mouthed PK's out there.. I would certainly not generalize ALL PK's in that nature however.

As for scammers.. most scammers I've encountered can't hold their own.. when busted, they have usually bolted or just moved on in search of another victim. This is why you'll rarely see them on Fel.. they'd be more fun to farm than some of the monsters in the game. *grin*