I recently joined this site after lurking for awhile. Are blog contributions of that sort are the primary purpose of Less Wrong?

It seems like it fulfills a niche that the avenues you listed do not: specifically, in the capacity of a community rather than an individual, academic, or professional endeavor.

There are applications of rational thought present in these threads that I don't see gathered anywhere else. I'm sure I'm missing something here, but could viewing Less Wrong as a potential breeding ground for contributors of that kind be useful?

I realize it's a difficult line to follow without facing the problems inherent to any community, especially one that preaches a Way.

I haven't encountered the rationalist tumblr scene. Is such a community there?