Looking at the above code a see a problem from an SEO perspective. The problem i see is that if “Special offers” was the key pharse wrapping it within Div tags makes it pretty much invisible to spiders.
I doubt search engines would care too much to be honest. It’s just a bit of markup and I seriously doubt that Google would have a problem with your header being inside a div.
Nested <div>s don’t make content invisible to search spiders at all. As far as a spider is concerned, you’ve got an <h1> that says “Special Offers” - it doesn’t care if that <h1> is sitting in the document root or is nested in a complicated structure of <div>s.
What I would say about the “end” comment is first, leave out the #, there’s no need for it there and you’re just inviting trouble if the server tries to parse it as an instruction rather than a comment. Second, if you’re opening <div id=“flowerRight”>, I’d make sure the closing tag is matched up with <!-- end flowerRight –> (: