I'm sure (or at least I'm willing to entertain the idea) that I'm missing out on something wonderful, but I know the plot of Hugo's novel, and as a source for an international musical-extravaganza hit, it seems a little less likely The Guide to Incredibly Communicable and Really Messy Diseases, but what do I know?
As usual the play, and the two movies, try, and do a decent job, to convey the themes in Hugo’s novel...but IMO, they miss (or leave out) some important things. However, I really understand that you can’t condense an entire book into a 2.5 hour production.
But the theme law/grace is what intrigues me about Hugo’s novel, and all film and play versions did get this across. The nuances of the theme were sometimes lost in the lyric of the songs, or the lack of more of the story to put things in more context. But all in all, the screenplay, composers, and lyricists did do a fine job.
I get what you are saying, and I don’t think you are missing much. I saw the live show around 1990. Aside from the sets, which were really incredibly clever, there was little there to impress me. I have no desire to ever see or hear the show again.