'heading' != 'paragraph heading' (in fact there's no such thing as an HTML paragraph heading). A heading tag is used to denote the heading of a section (a conceptual section, not necessarily a
<section /> tag) - it doesn't have to be above, or any where near, a paragraph.
If you're interested in SEO, whatever you do don't convert them from an
<h2> to a
<div> carries no semantic weighting whatsoever, while an
<h2> does. If you're not happy with
<h2>, obviously choose something else, but for the love of Matt Cutts not a
Personally the only tags I'd recommend are
<h2> (which is standard for adding a heading to a section in any website, not just a Drupal one) or
<h3>, if you're already using
<h2>'s to markup more semantically important sections elsewhere in the page.