It may be that the benefit of LessWrong skews towards autodidacts -- after all, EY himself famously is self-taught. With that said, I'd say hell yeah a studious reading of LessWrong can teach you more than a "typical core college class." Sorry to say a typical core college class is far less than it should be. There are a few excellent teachers of core classes out there, but the academic system just is not set up to provide proper incentives for introductory undergraduate teaching.

I'd agree with your exception for technical classes such as general chemistry, not closely related to the core mission of LessWrong. However, if you choose to get involved in computer science related discussions on this forum, you had better punch your weight.

A second related question is whether there's a possibility of building a college course -- or college-like course, perhaps a MOOC -- specifically revolving around mastery of the content in LessWrong (perhaps starting with the Sequences).

Aha, mastery is the question, isn't it? I have no full answer for that. I hope some other LessWrongers will have.

With that said, the stupid questions forum is potentially better for specific questions than you could get from most graduate student tutors.