OK, still on this unusual one-off … I've assembled a number of smaller .docx files (different contributors) into a single master for delivery, using Insert > Link. I found my way to the list of links, as well.

Three questions:

• how to delete a link? the Links panel offers Update, Change source or Break link
• how to open a linked file? Open source is greyed out
• how to specify automatic udpate? the Update method radio buttons are greyed out