First, I am not sure what you mean by "so few custom-build WP-homepages. Most I have seen so far just have adopted the stylesheet but not the whole layout"? Many designers use stylesheets to define their layout, instead of tables and such. But I see a lot that isn't "adopted," it's created. Look at my page. Every one of those layouts (except for the Vampire Prinecss Miyu) layout was created by me, and uses stylesheets as the source of the design. Even the Miyu layout was tables-based, and I changed it to CSS-based, but I did not create the images for it.
Does that answer that question?
As for a site that has a blog and static pages, well, you can see a small example of that on my page as well. My schedule page is "static," but the layout matches because it is a WordPress page. I basically just took out the WP loop and replaced it with my schedule information. That way, when the layout changes on my blog, it changes on my schedule page as well. I have also seen other sites that do something similar. I don't know how they do it, but they have pages other than their blog on their site, and those pages match the layout...AND they use WordPress.