Those aspects of the book are awesome but I think they run against the themes Ridley Scott was going for. Ridley Scott wanted Deckard to be an android. It's hard to interpret the unicorn scenes otherwise. The androids are shown as cruel due to their lives as slaves, but with human-like longings for life and meaning (like in Roy Baty's final speech about tears in rain). The overall point is to blur the boundary and say the androids can be meaningfully human.

Whereas Mercerism and the animal stuff in the book are all about emphasizing the ways humans are different from the androids. The androids mock Mercerism and they don't care about animals: they are incapable of empathy. They torture people and animals without compunction. The alternate police station scene, where Deckard is tested using a bone marrow test instead of Voigt-Kampff and comes out human, is evidence that he's not an android.

The book is, in my view, one of the few pieces of sci fi media that seriously raises the question "could these apparently human-like machines really be human just like us?" and answers a resounding "no". The androids are psychopaths who are unable to partake of the human experience. Ultimately PKD is concluding that they are meaningfully not human---and, furthermore, some biological homo sapiens who act like them might actually be androids, a theme you can find elsewhere in his essays [1]. To the extent that Deckard's humanity is called into question it's not whether he is physically an android, but if he is psychologically a psychopath because of his job killing androids.

[1] https://sporastudios.org/mark/courses/articles/Dick_the_andr...