1. Use relative path for the PDF files. The paths for the PDF files in the metadata should be relative to the "copy files to" path.

2. Provide the option to automatically personalise the citation keys, just like we can rename the files. It is not good to edit them one by one. We need it to be done automatically with some rule.

3. Put the first page number in the choice options when we rename the files and personalise the citation keys.

4. As mentioned by others, use the citation keys to rename the files.