I love the new footage and Zirconia. The music is fitting and i love it as usual. As for the 80 minutes: not sure what to think about it. I know this account was right in the past but maybe he/she is wrong this time around? But even if its true i can still see this working just fine as long as Venus Dream isnt part of the first movie. The usual SM and SMC episodes were under 20 minutes anyway if you cut out the intro, outro, transformations, title cards, speeches, next episode tease and some flashbacks/repeated footage. Even then i can see Toei shortening the first act of Dead Moon Circus saga. For example they can get rid of scenes like Mamo buying the caleidoscopes, talking weapons, animals transforming into trio (they can be introduced as regular minions and change back into animals after their human bodies get killed by the senshi which would be a way for saving them), Chibiusa trying to get back to 30th century and failing, maybe even getting rid of the scene between sick Mamo and small Usagi from Mercury's dream, senshi visiting the circus after Mars dream? They dont have to make big changes to make the movie faithful while having the right flow.
If Venus dream is included it might be a mess though.
Its also possible 80 minutes is just a rough number this person heard but it could be 80+ in reality like 85 or 88