Was the interview conducted exclusively, and only published in German? Could be that you can find the magazine it was taken from? I'm a white boy too, but I know the music a bit.
Poppen - boning, having sex - is this what someone like 50 is going to say? No. Try fuckin, screwin, doin... the whole sentence would be handy.
Olivia ist ein ganz süßes kleines Biest - a really cute little thing (thang) Not rough enough? I cant see how the author came out with süßes kleines Biest anyway? It doesn't feel right, and doesn't translate back easily. I'd need to see more context to help better; ie, what he actually thinks of the girl. A commonly used word is "nasty" or "freaky", but then I'd have no clue where the translation sprang from. Who's Olivia?
Sie sollen sich gehackt legen - they should fuck off? What does a gangsta say? Think more wortwörtlich? There is a phrase about slicing someone up (with a blade of course), another about "laying someone down" to mean killing them, aybe they were linked?
Ich reagiere nur auf ihre Beleidigungen und Frechheiten. Frechheiten - sass, lip? "I'm just actin on they insults and lip" - or, for more "color", go for something with the phrase "they('ve) be(en) running their mouths", to mean letting themselves "talk reckless", and so on. Tired, cant see the sentence in there right now.
too long for one reply...