I agree with every single thing you use said -- 1. admirable stagecraft, 2. time traveler effect didn't get tired, 3. script padded, 4. could hav been several hours shorter, 5. Anthony Boyle carried that show. I wonder how his replacement will measure up.
One more point, which I guess is obvious -- the show is really for people who are already fans of the books and movies. It's hard to picture this stage play alone turning someone into a similarly rabid fan.