Displaying multiple File entity types in a view, when they have different fields to display
What I ended up doing was just add custom tpl.php files for each of the types I was interested in (audio/video/images; e.g. file--image.tpl.php). Then, in the views, just say to render the entity instead of using fields.

I'd have liked a more elegant way, since I now have 3 more tpl.php files to worry about, but it DID fit the bill.