Many ways to skin a cat, as they say. Hyperlinks can be buggy at times but for your case I see no difference in having hyperlink text that just happens to be a document name vs a plain text field that provides some other type of linkage. If you go the latter route (plain text field) you don't need to show the textbox with the file path for the pdf for the record being viewed. However, you'd need code to deal with the plain text. If you made the path field a hyperlink field, you've just traded one field for another to do the same thing as you're already doing. It's just a matter of how you want to handle it. Surely you are doing this through forms and not allowing users to dabble in these tables and queries?
I find the subject interesting, having spent some time as a compliance auditor as well as a db admin for ISO 14001 and QS 9000 (I'm dating myself there, yes?).