html5: titles in sectioning elements - document outline and SEO implications

The html5 spec says that:

The outline for a sectioning content element or a sectioning root element consists of a list of one or more potentially nested sections. A section is a container that corresponds to some nodes in the original DOM tree. Each section can have one heading associated with it, and can contain any number of further nested sections. The algorithm for the outline also associates each node in the DOM tree with a particular section and potentially a heading.

and the same reasoning seems applied to the html5 document outline algorithm.

I've been checking my site's outline using the HTML5 outliner (h5o) [link] tool but am having difficulty achieving a clear outline that isn't overburdened with useless titles, because of the fact that elements such as

or will appear in your outline but will do so as 'untitled' unless you give them an explicit h1-h6 heading.

This seems frankly overkill for things like navigation or footers.

One solution is to replace these elements with divs, but that seems to defeat the whole purpose of using html5.

Another, which I've tentatively tried on my site [link], is to set headings for all sectioning elements and then use CSS to hide the headings for some of them (again, basically

and , as well as some

elements. Here's an example:

This results in a nicely-diplaying site, but the issue I see with it is Google ranking. In its Webmasters Tool help item [link] on 'hidden text and links', Google clearly states that:

Hiding text or links in your content can cause your site to be perceived as untrustworthy since it presents information to search engines differently than to visitors. Text (such as excessive keywords) can be hidden in several ways, including: […] Using CSS to hide text…

Some people might feel that whether Google likes the fact they use hidden text or not is immaterial, but most of my visitors come from Google searches and I'd rather not be penalized as a result of choosing to go with this setup.

Can anyone offer advice on the subject?