Don't let a file save unless all requried areas are filled out

If one puts a read only visible field on the top of each page, then a script could be added to the "Will Save" action to validate all the required field have been completed and if completed, then hide the visible field on the top of each page.

There is no way to stop "saving" or "printing" once the button has or menu item has been selected. You can add some scripting to execute before the "save" or "print" but you cannot stop it. You can use field to indicate the form in incomplete and hide that form field when the form has been completed.

It is not reasonable to prevent someone from saving a work in process. Why should you force someone to start over on a form if they are interupted by a meeting, phone call, emergency, or are saving in case of a system crash. But that is just my opinion.