Choong,
I'll have to take your word about the identification of pitcher 2, because I did not observe any sanguinea lower pitchers among the strands. Also, I've uploaded another photo of pitcher 2, which you may want to take a look at to verify whether it is indeed N. sanguinea upper pitcher.
Any thoughts on what Unidentified Nepenthes 1 (the one with the red peristome) could be?
Also, I know other Nepenthes besides N. reinwardtiana can develop the occasional "eye-spot" on the pitcher interior, but I was under the impression that this occurs very rarely, perhaps on one pitcher of the entire plant. As the plant I saw had two pitchers with "eye-spots", is it possible that it was N. reinwardtiana?
And finally, Unidentified Pitcher 3 is probably a hybrid?