Newb question about the use of h1-h6 tags

HTML & CSS
1

As I understand it, HTML5 contains sectional tags like section, article, nav, etc

I understand that the most important headings should have h1 tags wrapped around them and as the headings descend in the importance, we ascend upwards in the heading tags.

<h1>Most important</h1>
<h2>Less Important</h2>
</h6>Least Important</h6>

Is this document wide or only within sections? In other words, do is the following appropriate?

<section>
<h1>Most Important</h1>
<h2>Less Important</h2>
<section>
<h1>Less important</h1>
</section>
</section>

Or should it be

<section>
<h1>Most Important</h1>
<h2>Less Important</h2>
<section>
<h3>Less Important</h3>
</section>
</section>
2

It iks document wide in HTML 4.

It is proposed that it apply within sections in HTML 5.

3

And regarding how HTML5 uses heading tags, I would keep using the HTML4 setup (one main h1 heading per document, followed by a non-skipping set of lower tags as needed) until browsers and AT have caught up to the new Document Outline model. Currently, screen reader users and Opera keyboarders use heading tags as an important part of site navigation so the “make everything an h1” is currently a problem.