Regarding the preservation of movies digitally… Maybe they could design a new kind of disc based on the Blu-Ray who would be bigger (like a small pizza) so it would hold more data and they could design it to be stronger, but it would probably be costly…

As someone who fiddle a bit with computers maybe I can give my toughts on that… To preserve the movie for a long time it have to be stored in uncompressed format to not lose any quality, data on a Blu-Ray or DVD disc is compressed which mean the movie lose a lot of it's original picture quality, otherwise it would not…