Especially since Deckard had been his prisoner for a while by then, so presumably Wallace had ample opportunity to confirm he was a Nexus 8 or not. On the other hand, if Deckard was programmed to fall for Rachel, presumably he would have been more compelled to accept the revived Rachel - the fact that he didn’t isn’t just evidence of shoddy craftsmanship (wrong color eyes) -it is also some evidence that Deckard is human. Not that significant though, since we’ve seen replicants develop beyond their apparent programming.
That is not true - Scott filmed a unicorn scene for the original theatrical version. What has confused you is that fact that the unicorn scene he put into the 1992 directors cut is not the same unicorn scene as originally intended for the theatrical release (as stated in some of the coverage at the time) - Scott used a scene that he thought was better, rather than use his original unicorn scene.
Here’s an excerpt from the Wired interview with Scott where he confirms the unicorn was in the original theatrical cut:
Wired: You shot the unicorn dream sequence as part of the original production. Why didn’t you include it in either the work print or the initial release?
__Scott:__As I said, there was too much discussion in the room. I wanted it. They didn’t want it. I said, “Well, it’s a fundamental part of the story.” And they said, “Well, isn’t it obvious that he’s a replicant?” And I said, “No more obvious than that he’s not a replicant at the end.”
edit: Obviously just catching up on this thread and it seems like you’ve hashed this topic out as much as can be done constructively. Tom is largely right, but I do agree with one thing you said - that there is some suggestion that Deckard is a replicant in the theatrical release before the inclusion of the unicorn scene, but it comes across as more of a “there but for the grace of God, go I” tease that maybe none of us really can know for certain that we’re human.
I think your suggestion that Ridley Scott changed his mind post-release is nutty though. It’s not at all analogous to George Lucas telling us that he always wanted the droids to step in Bantha crap - it’s a fundamental plot point to the original story, and Scott would have to have repeatedly lied not just about his original intention, but about the existence of footage, the conversations he had, the role of the studio execs, the production debates, etc. He’s not a psychopath.