I watched this again at the weekend - still a brilliant film, and could easily compete in the cinema as a new release, IMO.
As for the replicant issue - I watched the Director's Cut but although there is some innuendo, I really don't think there's anything that points to clear evidence.
The only attempt to really stake a claim is with the Unicorn scene tying up with the origami - but this seems more an attempt by the director to suggest a point, rather than the actual script. As has been mentioned in the other thread, there's a lot of symbolism involved around Unicorns, and the unicorn scene insertion I never felt really sat in the film.
Issues such as Deckard climbing with broken fingers I'd put down to just artistic licence - "heroes" traditionally do such feats - and Roy knowing his name as a continuity/scripting issue.
That there were 6 replicants, 1 died, and only 4 to hunt doesn't necessarily implicate Deckard IMO - it could even imply Rachel was the 6th. And if Deckard had been among them, why no apparent recognition from the hunted replicants if they should have known him?
Personally, I don't think the film can have so much impact if Deckard is a replicant - it's a classic "man vs machine" exploration as a theme, and Deckard as a replicant weakens that considerably.
Still, there's enough innuendo to suggest the possibility, the script itself never really tries to offer any real evidence, IMO - simply applying a more interesting ambiguity to open up the scope of the film to possibilities.
The other obvious pointer to me is Deckards obsession with old photographs and sheet music, very similar to Leon's "precious photographs".
I personally don't think its really a "man vs machine" film at all as Roy and the other rebel replicants don't share much of a connection with Deckard. Its IMHO much more a study on the nature of humanity divided between two stories(Deckard/Rachael and Roy) that interconnect.