Opening attachments
 

I have an outline with a bunch of PDFS dragged into it.

If I click on the right-facing arrow at the end of the document's title, it opens the PDF in a separate Preview window.

If I click on the triangle on the left side of the document's title, it opens the document in the outline ... but I see only the first page. So it seems that if I want to see subsequent pages, I have to open the document in either a Preview or a Quick Look window

Is there any way to run through all the pages of a PDF attachment within the OO outline without opening it in a separate window?

Sorry, no, there is no support for multipage PDFs with the inline attachment viewing.