If you just want to discuss a topic, but don't have an actual question that you want to ask, then the appropriate place to go would be chat (of whatever site is relevant to your topic of discussion). None of the actual sites allow discussions (although meta sites are a bit lenient about it, but that doesn't seem to be relevant to you).
The site was designed as a question and answer site, and it has taken a number of steps to specifically inhibit discussions taking place here. The site owners simply felt that mixing questions and discussions make finding useful content harder, and there were already so many places that allowed discussions to take place.
If chat isn't the appropriate medium for you, then odds are you're better of going to a traditional forum or another site of some sort to hold your discussion.
As for whether chat should be mentioned on that page; I think that would be appropriate.