Are the human servers also Chasers? Or are they just people aware of the Crimson Sky and the weirdos that go to this place?

While I'm at it, how tightly-knit is the Chaser community? Do people usually just go solo? Or is it more common for them to go in teams? And is it small enough that everyone should know each other (unless they're newbies or loners)? Just trying to figure out if I should start having Rui-Ling note familiar faces and say 'hi' or whatnot.