Isn't Giuliani the one who suggested Sessions to Trump? Selecting Sessions was mistake #1 for Trump. Mistake #2 was trusting and hiring Giuliani. Mistake #3 will indeed be Christie.
I don't see it happening as Christie and Kushner aren't exactly best buds.
I'd hate to lose Ted in the Senate, but he would make an absolutely awesome AG and draining the swamp would indeed happen. If not, IMHO, Trump should be leaning on Ted who I think would at least give him some sound advice as to who would serve him well as the next AG.