Calibre for ebooks and kiwix for wikipedia both have a random button. I would like to see such a button in coollector. What is the general opinion on the idea?

Coollector is especially designed to help you decide what to watch. Why you want to go back to randomness is beyond my understanding

You have a drop down menu at the bottom of one of the panels in collector which says "ordered by". There you have "imdb rating", "year" etc etc. If you add "random selection" , you could add the functionality i want. Then i can open my owned or not owned files and simply select random selection. I could then browse for movies much more easily and discover some films I might otherwise have missed.

If you can't decide what movie to watch, you don't need a random button or any other interface change for that. You can just scroll the list randomly until your eyes stumble upon a movie that you're in the mood to watch.