What is considered off-limits in chat?
According to the Talk in Chat privilege page:
When should I visit chat?
- for real time collaboration
- to meet the fellow members of your community in a more social environment
- for less structured, casual (but still roughly on-topic) conversation
As this primarily pertains to this specific room, yes, I'd avoid going too off-topic. From what I've seen so far, we're still okay. Most of the discussion is related to site maintenance, which is absolutely okay.
One thing I should point out: the rooms can be seen by anyone. This is not only for moderation reasons, but also because the rooms are generally expected to help add some "side-knowledge" to the site (they are still not a substitute to main site posts). There are also gallery chat rooms, but the only difference is that certain people can post, but everyone can still view the messages.
Beyond that, off-topic discussion is not greatly discouraged. Small-talk shouldn't cause a problem, but I also wouldn't make that the entire focus. It still has to be respectful, of course. I will not hesitate to take action if things start to heat up, but I'm sure we're much too responsible to let it go that far.
I also leave you with the Definitive rules on chat rooms with non-technical discussion.
I think that you can go as far as you want in chat, assuming nobody there complains. Otherwise, I don't see any harm in being off-topic there.
And if somebody complains, just move the discussion to another room.