Opposite of a killing spree, where people would get murdered, people are just celebrating life.
Mouth full of soap could also refer to the parenting technique of making the child wash their mouth out with soap after they cuss. Lupe deliberately says “fudge wit it”, instead of “fuck wit it”, which a normal rapper would probably say. Although Lupe does occasionally swear in his songs, it is a lot less than most rappers, because his father did not allow swearing growing up. It wouldn’t be suprising if he told Lupe to wash his mouth out once or twice.
In “Cleanin' Out My Closet”, Eminem also talks about “skeletons in his closet”. But in that song he is talking about his family life, not a fictional incest rape.
Eminem claims that he is the reason he is a sucessful artist, not the shock-addicted Slim Shady. Slim Shady was just something he made up on his own, represented by drug use and blonde hair.
Eminem has a picture of Hailie tattooed on his arm, so he “gives” that arm to her.