when you're talking about the head shake/wobble, is the movement really dramatic or is it subtle? when Coffee Bean first came out of the bag she had this subtle side-to-side head shake going on; you could only tell if you held her still (you can see it in my unboxing video 2:04-2:08). knowing her personality now, i can only assume she was scared out of her mind. there is no sign of a wobble now and she is 100% healthy. all this said, she moved just fine and never had an issue crawling into her hide. not being able to move in a straight line does not sound okay.
definitely call BHB and let them know the situation, and also keep a close eye on the snake's behavior.