(I may be misinterpretting your message, but...)
So what we have is a tie between page and document, and this bothers
you. Does <link rel="next" ...> and <link rel="previous" ...> really
not need your needs? It's a simple matter to write a browser which
displays a document (== a page) and then at the end, you could press
the spacebar and magically, it continues onto the next document.
Browsers really should have next and previous buttons which correspond
to the <link> tags, apart from the "last and next page visited"
buttons. But there is nothing to keep you from printing a "muli-page
document" which extends accross several HTML documents, or from
displaying linked documents together, via the behavior you described
or another.
-Fred
tritan@mit.edu