Good question, Nick.
I think you summed up what most of us want pretty well, a hassle free place to chat, or to lurk while chat takes place about SEs. I do think that provided the majority of threads are not OT, we are following the spirit of the charter.
I've enjoyed U.R.E.S. for a number of years now, and have enjoyed meeting a lot of the posters, quite a number of whom I count amongst my friends. I came to the group as a totally ignorant newbie, and thanks to the combined efforts of all concerned, I'm now only partially ignorant :-).
I'm very heartened that this thread has brought out a few infrequent posters. My message to lurkers is that the group will only prosper if those of you who enjoy the group also join in. There will always be some loss of people from the group as personalities clash, people move on from the hobby etc., so some new posters are always welcome.
Perhaps another question to be considered is: what do we not want from this group? One simple answer is trolls, obnoxious idiots who thrive on stirring up arguments. I'm sorry to state the obvious, but based on recent experience, it's worth stating. There is only one way to deal with trolls, DO NOT REPLY to their posts. To labour the point, if you think someone is posting just to provoke argument or to slag off the group, just ignore it. If these attention seeking individuals get no attention, they will get bored and move on to pastures new.
Regards, Arthur G