In the videos to his Chronic singles (and in the songs themselves) Dr. Dre's 1964 Impala has been fitted with hydraulic lifts which raise up and down. The girl's ass is being compared to this phenomenon.
Keep a prostitute working the streets as you were her pimp and keep a cigar (Swisher Sweet is a brand of cigar) full of Marijuana instead of tobacco. Pine is a slang term for marijuana because they are both green
Playing rapper Too Short's music at an appreciative volume, out of a Red Candy Apple color painted vehicle (most likely a 4-door sedan from the '70s/'80s-ish, maybe convertible).
TI is saying that even though he is rich now, he would still be willing to participate in a robbery of the sort where he would have to kick in someone's door
to be more specific, i believe to "bust" a gun is short for "bust it out" as in pull it out of wherever it was previously concealed, which implies you won't shoot but also won't even have a gun to take out