Umm, you can probably set it to view for staff & donors or something. I think its the best way to use it.
Just set refresh time to ~12 seconds and it's good. About forum activity, it could affect it based on experience.
I'm not sure about that, Blue, though it does seem to be the popular belief. My take on it, though, is this: perhaps it only seems to do that because there isn't much activity on the forums in the first place. In other words, most of the content on the forum isn't interesting, and doesn't promote interaction and discussion. Someone sees this longed for interaction and discussion in the shoutbox, and thinks that it could have made its way into the forum instead. But whether it would have made its way into the forum if there was no shoutbox is indeed the question. That said, if interesting new topics are regularly being submitted to the forum, it shouldn't be a detriment. Also, having members chat with one another on the shoutbox could spill over to discussions because the chatting members, already acquainted, more freely open up to one another. That's my theory anyway. I use Cyb's shoutbox.
It doesn't take up load on my forum. It loads fine. Cyb - i used it its helpful. But inferno shout takes up alot of load.