i definitely felt the need to avoid the NHK ni Youkoso forum for a while because raw viewers were way ahead of the rest of us. Many of the raw viewers had also read much of the manga, so there were discussions swirling around the anime vs. manga issue as well. There were many polite participants who used spoiler tags liberally, but the occasional impolite contributor can really ruin a story with an inadvertent revelation. Also it gets tedious to see a discussion with a dozen consecutive posts in spoilers and know you don't want to read any of them.
I also felt something of the "old news" problems in this forum as well. By the time those of us watching subs caught up, the raw viewers were discussing issues three to four episodes ahead.
I don't really see how it would hurt to have an "unsubbed" category along with subbed and licensed. I don't know if every series would end up in both categories, but we're really only talking about a few dozen threads at any one time. Given the speed with which threads come and go in these forums, it doesn't look like we'd be adding a lot of overhead by setting up a locale for people to discuss raws.
I'll often resort to spoiler tags even for series that have finished because I'll want to discuss critical events that someone new to a series hasn't yet seen. (See
my discussion of Blood+ for an example.) Most well-intentioned contributors here do the same. But then there are the people who complain that they can't figure out how to insert spoiler tags. I observe in passing that the "quick reply" box does not offer the spoiler option, so we're relying on participants' willingness to delve into the advanced composition form to use spoilers. I think that's asking a lot of infrequent or new contributors. Adding a spoiler option to the quick reply form might help in this regard.