Wow, quite a hand built car story.
It does sound like you had quite a few issues and on top of all those they happened on your maiden voyage which you had decided to film hollywood style. Maybe if IM would have been involved in the scheduling of the filming of your car they would have sent support with you for the ride.
My advice at the moment you discovered all those issues, would have been to return the car right away to IM, it is obvious from your story that it needed to stay with IM for more sorting. Sorting issues and screw ups to the extent that you have written about are really unfortunate but this list has a number of horror stories in the learning curve of what this hobby of hand built cars is all about. You do not know what you do not know about this hobby until you live it. I am sorry for the pain and aggravation that you have lived in sorting out your car , I know it well, and yet, I am really enjoying my car it will be 5 years in April that I took delivery.