So, uh, did the city take him prisoner? Since he's not allowed to leave? It's like, ok, he can't join the adventurer's guild, but does the guild really have the authority to keep him inside the city when he's not even a member? How do they even have the time and resources to keep a bunch of people inside the city? Makes no fucking sense.
I've been wondering for a while now if this is just a really bad adaption, and these things are more properly explained in the novel, or if it's just as nonsensical.