Knock You Down
Joe Jackson, father of Michael Jackson, was an alleged abusive father to his children. This is a reference to his short temper.
This line is in reference to a song by artist Joe Jackson. Jackson's best known song would be "Steppin' Out." Kanye proceeds to rap, "Now, I'm mad, real mad Joe Jackson", which translates to "I'm mad, so I'm Steppin' Out".
NASA is an organization that runs the space program. it symbolizes a far reaching destination. West is saying that they will excel towards thier goals once they're together.
Slick Rick is an 80's rapper. His song "Hey Young World" conveys the message that even though its cool to be a hoodlum, you should try to make something of yourself. West is saying she should leave Ne-Yo because she's better off with him.
before he got serious about a woman he is interested in, he used to engage in many pimp-like activities such as pursuing sexual relationships with various women
Kanye would like to know if this lady can get over her past (ghosts, from Casper the famous friendly ghost)
Kanye is saying that in his angry state he could be compared to Joe Jackson (Michael Jackson's father), who has a reputation of being an angry and mean person.
Kanye is saying that the situation he's experiencing is bad, and he uses Michael Jackson's name because Michael is strongly associated with the word "bad" because of his song called "Bad"
this seems to be a racially offensive statement, as "casper" is sometimes a derogatory term for a white person (after casper the ghost) - Kanye seems to be asking if this woman can see past her white admirers to choose him instead.
keep pursuing what you want (by putting down others, which in turn raises your confidence), whether you're rich and wearing expensive Louis Vuitton clothing (as in Vuitton/button -ing a shirt up) or of average wealth and wearing affordable Reebok shoes