That's a lot of work!
I think what I write below is already things you know but... for what it's worth I offer my thoughts:
a. What is the narrative storyline ?
I didn't really feel I caught much of a narrative until near the end because the visuals very definitely set the scene for illness/injury at the hospital.
I think I lost track of who was who just a little and some of that might be due to similar coloring on the characters.
For instance, I remember a car driving from right to left but I don't recall who might have been in that car and I don't know what became of it or it's driver.
In hindsight, perhaps it's the guy who runs across the road and hugs the motorcycle driver.
There is a guy with binoculars but... not sure where he was watching from etc.
Is it possible that all of these four are the same four that are in the waiting room at the hospital (I'll have to watch again to confirm).
So, at times I wasn't sure if a new character was being introduced, if an known character was reappearing etc.
As you suggest, I do think audio will very likely resolve some of these issues.
Although I think I know who is in the hospital bed... mostly because I've been following this topic... I am not 100% sure in light of the viewing of the video itself so I need to go back and view the video again to be sure. Similarly, I am not entirely sure what put that person in the hospital although I seem to recall the answer to that from the discussion in the forum too. I will guess that an audio cue may be added later that will lock that down.
So, "errors"/"faults"? I think taking a good look at the transitions from scene to seen with an eye for where the viewer's eye is most likely to be and then motivating the camera to move/cut accordingly would be ideal. Upon subsequent viewings I should have more to say but I want to capture my initial thoughts on first viewing. The second thing would be to find some bold contrast to differentiate the characters a little more. An example of the sameness in contrast might be that of the character with a beard. The beard didn't initially register and in the process of confirming the character had a beard I may have missed some important narrative beats.
any errors or faults you can spot that I have missed ?
It seemed to me that a few sequences started from a halted/stopped position rather than 'in progress' which might have detracted a little from the narrative flow.
When the camera 'clicks' started to kick in and the photos were being taken... that sequence read very well although now that I think of it I recall the bearded guy but am not 100% sure who the other person was.
P.S. I was NOT prepared for the audio to suddenly start after the prolonged silence. That definitely woke me up!
I need to be more careful with my volume.
I will look to see if there is any specific area where I think a transition can be adjusted.
At a guess I'd say several could either be shaved by a few leading frames or refashioned via a cross dissolve.
A stray thought: I wonder if there might be a few narrative 'tags' that might help the audience to keep tabs on characters. A few possibilities: color (the 'pretty' girl in purple is a good example of this... she was easy to spot). Having the others wear clothes that do not match that of others might be useful. For instance, one character might wear very dark pants but none of the others wear dark pants. One might wear a tie while none of the others wear one. Certain characters might only (or primarily) enter and exit the screen from the same side or 'own' a specific place on the screen more than the others. This might translate to depth where one character (the grandmother) is free to move in any dimension etc. but others are constrained to move only to the right... only to the left... occupy a specific distance from the camera... just random thoughts here... not necessarily suggestions. I think... but will have to check... that it might be good to have a few more closeups of characters so that we can see and recognize them easily. For instance, in the waiting room we see them together so a closer view from one to another might aid in recognition especially if it 'matches' or echos a scene we've seen earlier. Ah, that that guy... that girl... etc.
Keep on keeping on. That is an impressive amount of work.