I agree with pretty much everything you said (except for the sl4 stuff, because I haven't been a part of that community and thus have no opinion about it one way or another). However, I do believe that LW can be the place for both types of discussions -- outreach as well as technical. I'm not proposing that we set the barrier to entry at zero; I merely think that the guideline, "you must have read and understood all of the Sequences before posting anything" sets the barrier too high.

I also think that we should be tolerant of people who disagree with some of the Sequences; they are just blog posts, not holy gospels. But it's possible that I'm biased in this regard, since I myself do not agree with everything Eliezer says in those posts.