I seriously doubt she'd have a problem with "Let the kike flow". Most comedians hate censorship. Nothing's of-limits to them, as long as it doesn't alienate their audience.
And I don't know where you're hearing about white people laughing at slavery. Black folks were laughing loudest at my theater which was about 60 percent black, and all of the disturbing or traumatic slavery scenes were treated with silence or sounds of concern by the entire audience. You guys act like race riots are gonna be sparked off this.