Hello,
For the first issue that you mention, where related documents are not shown on the Finished Production Order, please refer to ZTN4282 for information on how to configure the results that are displayed in the Zetadocs Document Factbox.
For the second issue, please refer to ZTN4274 for information on how to add Zetadocs Document Factbox features in non Sales and Purchase areas of NAV.
I hope this is helpful.
Kind regards,