After adapting this page to the current views, I looked at the "more advanced" pages and I think there's no longer a point in keeping a separate introductory page and then a page targeted at stronger players, because 3-3 is so ubiquitous these days.

Also, I "cleaned" some of the Q&A.

I agree that having two pages is redundant. IMO, it's okay if SL articles have more advanced sections -- most of us are used to Wikipedia where an article on "nuclear physics" has some parts that are easy to understand, whereas other parts of the article fly over our heads -- and that's okay. People know how to read Wikipedia, and dense subjects simply need to be organized better.