>Apparently some footage from "The Shining" made it into the U.S. theatrical cut. Who knew?!
That was fairly widely known, ever since the Director's Cut in the 90s, and again later in the internet age when Scott released the Ultimate Edition. What was new to me, however, was that the footage was given by Kubrick to a fed-up Scott, and the difference in aspect ratios made this re-purposing possible (otherwise there would be a VW Beetle in Blade Runner).
On a tangential side note, some people important to Scott's film Alien (Dan O'Bannon, HR Giger, Chris Foss) were first assembled by the director Jodorowsky for an abandoned adaptation of Herbert's Dune. Dune is set in an apparently post-AI universe, long after a human crusade to destroy all AIs in a 'Butlerian Jihad'. A similar issue is explored in Iain M Bank's non-Culture sci-fi novel The Algebraist.
And yeah, in interviews an exasperated Scott has confirmed the theories about Deckard by pointing out a detail in what should be the last scene (before the extra Kubrick-shot footage was bolted on); a character dops a certain item on the ground. The actor playing him would later play Admiral Adama in the new Battlestar Gallactica.