I also took a look at the HTML/CSS files, and I don’t really think the files it produces will work for you. In the long run, it’s probably going to cause you more headache than just laying things out in RW. You’ll have much more control over how things look across all device sizes this way.
The HTML stack is for coders who want to do some of the layout in actual HTML code. It really isn’t designed to pull complete HTML pages and associated CSS into a RW site. If the HTML/CSS was simple enough, it could have worked.
The HTML stack, is for inserting snippets of HTML code into an existing stacks page.
What you’re showing “DT” produces is very outdated entire HTML page.
Rapidweaver does offer an offsite page, but you would lose all the navigation and styling. You also could try to run the pages DT produces as an iframe within RapidWeaver, but with non-responsive pages like DT presents, it probably wouldn’t work very well.
The only other thing I can think of is to learn enough about code, to pull out the chunks you need from the Code that DT produces.