I totally agree with you! In fact classical music hadn’t always been so formal, and it’s only been so formalized in the 20th century. Bringing back audience participation would actually be a revival of how things were. I guess going forward if people can see how successful such concerts are, maybe they would gradually change their mind.
As for combining tech with live performances, where do you draw the line? I mentioned briefly about the tech person being another performer in the piece, such as through directing visualization changes that are timed to the music. We can even add fog and floodlights at appropriate moments in a piece. Do you think this would be too distracting, or could this be accepted as concert basics (i.e. almost all pop concerts use these tools)?