Document Management (DocMan)

Is it possible to make Digital Signature integrate to attached documents through third party application?    

Is it possible to replace physical document file with a new file in Document Revision window, on RMP Delete is available. after delete, upload of new file seems  not available.

One customer that am handling is looking for a quotation to add a “delete” button for NCR. Customer mentions the following:We need to be able to remove incorrectly reported cases from the system (like we do in DocMan). Same goes for CAPA cases, where we also have some test cases that were logged in production environment by mistake. We also need to be able to remove these.The delete option should only be available for our global SuperUsers. Would like some quick suggestions ?