i don't mean to be except this to everything but that's the only thing I can think of. Basically, IMO, you are saying this for specific things but in general off-topic chatter doesn't matter. Also with the Facebook thing, off-topic chatter they should be somewhat lenient as they might be discussing news so it can be accurately described.
I've seen two types of discussions branch out from the facebook threads, one is clarifying and expressing different point of views of a situation, which I believe is fine. The other basically comes down to arguing with the posted topic and becomes propaganda.
I do welcome both types, I'd just like the different views in the thread and the propaganda happen on facebook itself.
I do think the mods are lenient on those threads, it's a learning experience for all of us and we'll eventually find the happy median.
