As shotcut now has markers, automating clips might be the next suggestion.
To talk clearly, I will make a video very soon for it. But right now I will explain with text.
So, when we create markers, we obviously do it to organize stuff. But my suggestion is:-
If we create a marker on a empty timeline, and select some clips from the playlist to add, then go to the automate clips on timeline under the edit menu, we would have two options, automate according to: selection (1st option)/sorting (2nd option).
Choosing selection should randomize the order of clips. And selecting sorting should sort it on the timeline according to the letters or creation date or something like that.
And after pressing ok, it should cut and place according to markers.
Sounds like a Slideshow Generator with variable slide durations. What’s the use case? Synchronizing the slideshow to a soundtrack? Most soundtracks have a set tempo, so how often would variable durations be necessary?