Take heed to the first section of Krashnicoffs post though. It's exclusively used by immigrant gangsta wannabe brats, so don't start spouting those words if you ever visit this country. Swedes saying those words are called hobbyturkar(Hobby turks) here. I guess that's slang?
Ehh, no it's really not.
Granted i might be a bit biased, moving in a lot of graffiti and Hip Hop circles but a few of these words are not that uncommon. Jalla for instance.
I do suspect it might be a class thing and also geographical.
And your comments about the people who speak in this slang really just come of as incredibly condescending.
I do not feel that it's right to shame or trash-talk young people who are trying to find a cultural identity, it's really no different from any other sub-culture out there.
And just implying that it would be wrong of a "Swede" to take after the speech of young immigrants is distasteful on so many levels.
But yes, a tourist or someone visiting Sweden should probably not try to use any sort of slang during their initial conversations, they might come of as a bit odd.