The link text on the JS page is quite repetitive.
I'd fix myself, but they are in some special include somewhere, rather than directly in the source.
Yep, this problem happens on a lot of listing pages at the moment. We make extensive use of sub-pages, which is somewhat non-standard for MediaWiki.
The API_listing pages (see http://docs.webplatform.org/wiki/css/properties for an example) do the right behavior, but for technical reasons can't be rolled out widely yet.
I don't see this issue currently.