Predxeno, I noticed that you wanted some footage of Newt's Authopsy on the Anthology. While there is not actual footage, in the Photo Archive of ADI's Workshop in the Alien3 section of Disc 6 you can find stills of the model they built.
Regarding the films, I've watched Alien in blu-ray. f**king Awesome. Film got a make over and it looks great. Almost like it was released a few months ago.
I had a quick look at the memorable moments of the other flicks.
Aliens is alright.
Alien3 looks great too, except for the ginormous downside of the Alien still being Green-blobbed all around... sad face.
Alien: Resurrection is.... damn, disappointing! D: They could've done a hella better job with it, it's like they didn't care much. :/