As far as I know - and please correct me if I'm wrong >.<- he always teleports as whole person- and others who touch him go with him (so as in the movie where Beast holds him). I followed that way, his powers work... and because he and Kurt are touching, it wouldn't work
doesn't kurt also teleport as whole person and has to take the ones with him who he's touching? ... how I said, I followed the way the movie took it >___< didn't figure out that it could work just for parts
Kurt has been shown teleporting without his clothes once, when he was in a rush, and he didn't take anything/anyone with him, so he probably just needs a bit of time to calculate.
Well, thant it is possible to get out of this mess without his mother. But since he's a toddler there and absolutely fascinated by the butterfly - they need Mystique xD