As I said, we are fairly well positioned in "G" and don't want to do damage...
Then don't be too concerned about the small stuff, which fiddling with Hx elements and other little on-page factors is.
Always try to build your backlink profile, continue to develop good content and -- *as the big "G" continues to evolve* -- seriously consider joining the social media movement.
Search technology, and thus SEO, has moved quite far from where it was, say, just five years ago. In my mind, once a site is technically sound with reasonably optimized pages, there really isn't much reason to fiddle more on the detail level, but to look more towards broader strategies.