Vamp Xander is a messed up puppy for a lot of reasons, and Willow certainly hasn't helped. Xander's still undusty because of Spike and Faith, and pretty much for no other reason. Spike's in an odd position of not only being human, but in essence is Xander's 'acting sire' (for lack of a better term) because Xander keeps trying to define himself as something he's really not anymore.

You're close to the "Kennedy complication," but you're a little off on the cause. :-)

And, yeah, Buffy is definitely out of the loop on a lot of things, but she's also bearing information. She's essentially the in-house Kennedy expert for Xander.