I agree that a strong attraction should not depend on the backstory or queue, those have come to be effective tools in themed attraction storytelling. I'm glad we've moved beyond switchbacks (as in classic Fantasyland dark rides) to immersive themed queues. I look at updates to the Jungle Cruise queue as pretty significant to the storytelling and placemaking of that attraction. It seems newer, "you're in the story" attractions tend to use the queue as major storytelling devices (with differing degrees of success, in my opinion).
Yes. And like I mentioned, pacing is hard to gauge based on an edited, fixed-gaze POV video, and story can be difficult to discern based on muffled audio.
I wanted to avoid spoilers ahead of my first ride later this year, but I went ahead and watched other/better videos (like the 360º video) and like a total nerd, I paused the video multiple times to examine scenes. I'm not sure if this gives me a better or worse idea of how the story is conveyed through an actual ride through, but there do seem to be things that support rider's understanding and experience of the story that were not obvious or even visible in the initial POV video.