HTML code into a wordpress theme and make it look like a website? Why do you want a wordpress installation then? try static front page, if thats what you are looking for
I always recommend Thesis... Search Engines love it for some reason, its supposed to be really customizable although I haven't gotten the hang of it yet I bet you could accomplish this with it though.
That's what I do for every site. Custom homepage with WP custom fields tied all into it. Just make it yourself and turn it into a WP theme.
If you're not going to use it as a blog - it's not going to be treated as a blog. Might as well just use HTML. It's not like wordpress outputs anything but HTML anyway. So spiders wont even know the difference. Besides, if it's just a sales page.. why do you care about it being crawled more often?
Google will know the difference.
shouldn't it be easier to get better SEO with a blog then with a regular site?
No. Why would you think that? That is a myth. The reason wordpress blogs generally rank higher is because of the structure of the html it outputs. Google likes how wordpress structure the content and links. But it does nothing but spits out HTML. Nothing else. Anything you find on a wordpress page you can put in an .html file. It will look the same.. and google will treat it the same.
So it would be pointless to do this then?
Is there anything "special" in the coding that helps the ranking?