I just ran a query related to the first question that came up in the queue I was asked about (rollback on DML). Number 6 in the list that came back was this post: Question on Salesforce rollbacks on dml operation. The only non-SF doc that came up ahead of us was a Jeff Douglass Blog post from 2010. In retrospect, I personally think that particular rollback post was a duplicate of the one that came up in my search and also could have been improved (or vice versa, not certain now which was created first). But then, I also misinterpreted the original post we were questioned about because of the way it was phrased or written.
I should add that the next 4 posts that came up were all posts from here, but not the post we were asked about. Perhaps I didn't use the right search words? (Salesforce all or none DML)
I've finished my review of all the posts.:)
During my review I came across one post, where during a Google search, I found what seemed to be something worth contributing to it. The post was about multi-picklists with the same items not appearing in the same order. Like others, I didn't come up with anything that documented this was normal behavior, only comments that said it was normal. But, I did find very clean Formula code which I added to the post. It wasn't entirely clear in the post exactly what kind of code they wanted, so I thought having Formula code would be good to add to it, esp for someone who might come along and read it later.
What I noticed more than anything, were the number of posts where the originator never accepted an answer, or where someone walked them through debugging their code, then the person wrote up the final working code as the answer and finally accepted it as their own. I thought this didn't show very good "sportsmanship" (I think that's the name of the tag used here) or more accurately, displayed poor manners and appreciation for the assistance they'd received.
I also saw posts where the originator (the OP) asked a very specific question, was given references to documents that essentially told them "it either can't or shouldn't be done that way" and additional information along the lines of "here are some alternate ways of accomplishing your intended purpose". I thought those were well done, especially when the OP responded with "but that wasn't what I asked!" with you jerk being implicit. I saw a great deal of patience and restraint exhibited in posts like that which I think is highly commendable.
It seemed to me that some of the questions still had a fair amount of vagueness to their quality when I reviewed them. That may be in part be why an answer was never accepted in those particular cases. At the same time, on many of those, there were comments asking for clarification that I'm not certain if they were ever responded to. If they were, in cases where the responses might have been through edits, it wasn't totally apparent to me; presumably because I don't have enough points yet to view the edits??