I found a workaround for my display related article links problem. It's not very elegant, but it works.
I set up two field per related article type (in my example two each for actors and for directors): One is a Field X of related articles pointed to the category I want and the other is a checkbox dynamic field.
In the admin view I have both fields, so I have to enter actors and directors twice per film: Once as checkbox selection and once as Field X / related articles.
In the content view I put the Field X in the position where I want to display the list of actors or directors. The Field X of related articles is automatically rendered with correct links to the actor / director articles. The checkbox selection I put in the "Hidden" position. This is only needed to automatically populate the lists on the actor / director pages.
I appreciate that this may be too cumbersome for user-driven sites where users woudln't understand why they need to put in the same information twice. But for my purposes (I am the only one entering info) it does what I want it to and I don't have to spend more time trying to find a solution.