You can show File Path on Title Bar in Excel and Word by creating and running a Macro - and even in Quick Access Toolbar too. This post explains the process in detail.

Microsoft Word has a date field, but it's not easy to use in an expression. If you need to update dates in a document, use Excel to calculate the dates and then run a mail merge.

If your source data is in Excel and has duplicates, run Power Query to remove those duplicates before running a Word mail merge.