The paper unicorn was over the top, so good. I dont recall ever seeing any hint of Deckard being a replicant in the book, possible i missed it but i remember reading something that Ridley Scott said the answer was obvious...i mean theres way too many little things in the movie that point there but Phillip Dick still disagreed.
Unfortunately you're probably right on the sequel front to but i didnt ever see the numbers on how it did on the asian market, that could be a deciding factor.