maybe nate asks blair to move in with him cause her bullimia is back, and he wants to look out for her. or maybe it has to do wiht his granparents. i think he's just trying to look after her, i honestly dont see them having any sparks.
i agree with cherryblossomjen, i believe that the baliranoid clips have to do with hte play, cause did you see nelly yuki's hair?! And was that carter banzian saying blairanoid, or nate's cousin?
i love your idea, but from what i've heard; chuck and blair are going to deal with some personal issues before they get back together. These issues have to do with what happened on NYE.