Biggest irritation for me is the game telling you to do something that will damage your rapport with them without telling you it will damage your rapport. Classic example is getting a writ to make a cheese plate and then Bastian has a fit.
(And, like, why? No one's asking him to eat it.)
Also, the idea of of Bastian being lactose intolerant is so anachronistic and not part of the world of Tamriel that it's really jarring when he talks about it.