I have successfully copy/pasted code from Dreamweaver into
SharePoint Designer, and imported images and scripts into Designer
so the relative paths resolve. I found your post because I'm
searching for info about using only Dreamweaver without Designer as
an intermediate step.
to be honest, you're better off using Web Expression --
Microsoft's latest answer to FrontPage, which is now dead. It was
designed to work with Sharepoint and files created in ASP.NET 2.0
much better than anything else out there.