Is the profile of the author publicly available: no.
I do not see what is going to make a link. Unless the link to the pictures of the author, then yes it is more interesting especially in colaboration galleries.
you're right : this feature is very interesting and not just for collaborative gallery : a gallery can represent a studio with several photographers, or a group of artist
Talking about that, I think our next target should be the artists in general, by making more features like showcases or portfolio, and more themes in this way
In the core, or in the Community plugin ? that's a good question. Can you open a "bug" in the bugtracker please ? http://piwigo.org/bugs thx