A client recently asked me whether a tabbed collapsed section of text that is expanded (i.e. revealed) when clicked, is an OK thing to do without negatively effecting SEO. I told him that for starters, he may want to rethink why he would want to hide the text in the first place (this is not an FAQ type scenario). The reason has to do with the aesthetic of the page. Anyway, aesthetic aside, any thoughts on whether a collapsed (hidden from view) negatively affects on-page SEO? Thanks. 
Stephan

If I want to have a cornerstone "page", can I substitute an actual page with a category archive of posts "page" (that contains many posts containing the target key phrase)? This way, if I make blog posts about a certain topic/ key phrase (example "beach weddings") and add a canonical URL of the category archive page to the individual posts, am I right then to assume google will see the archive page as the cornerstone page (and thereby won't see the individual posts with the same key phrase as competing)?