definetly good posting sujin..
I always feel badly when that happens, because I wish I could help more but can't seem to find a way to help..
Sometimes I go into chat and just want to hang out and not be alone, but don't really want to chat
What I usually do in that case is say something to that effect can be as simple as "hey guys, don't think Im ignoring you but I kind of just want to sit quietly with you guys and listen"
or even a simple " I dont really feel like talking right now" will do
And yes, as soon as someone goes into support chat, I typically follow as well to make sure that person is ok.
Another thing is, as far as I am concerned, if ANYONE is in chat with me and is upset or anything, by all means say something right in the channel. Again, it can be something as simple as "Hi guys, Im feeling rotten".
With newcomers it can be hard to get a feel for the room. Whenever there is someone new in the room that I have never seen before, I usally try to ask them how they are or something

Good icebreakers for newcomers can be anything from asking the room how they collectively are, to just saying hello!