You can use Mapsoft’s PDFSplitter tool to split an existing PDF file into separate PDF files.
You can choose to split the file into a new file for each individual page within the existing file, or you can specify the range of pages which should go into each new document. In this way it is possible just to extract those pages you require from a large document and ‘leave’ the rest.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.