I think /r/SlateStarCodex fulfills some of these. As a Focal Point/News Organisation, we see that it is evolving to a general rationlist-ish subreddit with about 9⁄25 articles on the front page not being written by Scott. In terms of the Stack Overflow-like function, with about 4⁄25 front page posts being questions related to various SSC/rationalist things.
I think /r/SlateStarCodex fulfills some of these. As a Focal Point/News Organisation, we see that it is evolving to a general rationlist-ish subreddit with about 9⁄25 articles on the front page not being written by Scott. In terms of the Stack Overflow-like function, with about 4⁄25 front page posts being questions related to various SSC/rationalist things.