Here's the solution I've thought about. It's not exactly a disagree button. But, it's a similar button. If enough people press the button, the post would become less visible. If even more people press the button, it might be hidden and referred to the moderators, and if even more people press the button, the post would be removed altogether. In addition, I could set it up so that this button would not be available to everyone, maybe just members that have been around a certain amount of time.
If I did this, I wouldn't be able to implement it right away. But I think it might help filter out the more offensive/combative posts.
Did you decide against this? I think now would be a good time to try it. There isn't a lot of negativity or in-fighting at the moment, so I don't think it would get abused. However, if someone started to bait someone into a nasty argument, we the people could show our displeasure with behavior and the poster would see that in their fading post. It would be a way of letting each of us know how much our peers are willing to put up with in a non-confrontational sort of way.
Isn't it at least worth a try? For a little while?
There are two types of people in this world: Those who can extrapolate from incomplete data.