Trying to answer the question "Is Deckard an android?" is pointless, as the Director-approved answer ("yes, of course") leaves us with a vanilla boring story, completely wasting the wonderful hints that Rutger Hauer in particular gave us to go on.
Consider: If Deckard is an android, he and Rebecca are just two machines making the beast with two backs. If not, he has all sorts of issues, not the least that he is a child molester (Rachel is six years old).
And the machines he is "retiring" are children, as can be seen occasionally when the actors let it bleed through. The scene when Roy Batty berates Leon is a case in point, when the conversation and facial expressions suddenly take a turn into the childlike, and the Deckard vs Batty sequences are full of occasional kid-level mischevious looks on the part of Batty. And of course, there's the wonderful performance between Pris and Batty in J.F. Sebastian's apartment.
But if Deckard is a machine too, he lacks the empathy for that to have any personal import and there's no point of inner turmoil.
I could go on, but all you have to do is watch and the actors show you a much richer set of possibilities than the internet Android-Or-Not combatants.