I always thought that Angier, like Bordon, cloned himself just once, and then, for his 100 performances, again like Bordon, used that one clone for the show. I did not think that he cloned himself every time, because if he did, there would be 101 Angiers at the end of the shows. So when Angier drowned, I also did not think about him setting up Borden, I actually never thought about that. I just thought that he, the real Angier, had set up the show so that there would only be one Angier in the end (not just end of the show, but end like during his retirement). We also do not know how many shows there were out of the 100 before Angier died, so did Angier want to go through with all of his shows, or just some, until he could get Bordon? I thought that he would be the one appearing at the prestige, and his clone would drown. If he used just one clone every time he performed, did he use the machine every time? What machine would he have used? If he didn't and used the machine every time to clone himself every time, how did he know that it would work every time? Like Tesla said, "An exact science is not an exact science." How did he know it wouldn't stop working on him like it did for Tesla? But some things are made clear when I think about what Angier said, "Every night, I did not know if I would be the one in the box, or the one at the prestige."
Quite a few questions but here it goes:
The movie clearly shows 1 Angiers always drowning. He used the machine each time he performed the show to clone himself and then killed the Angiers that stayed on the stage to prevent multiple Angiers from walking around at the same time. This is part of his vanity as he wanted to get all credit. He could have cloned himself once and done something like Bordon but that's not in his nature. In the last scenes of the movie you can also see the past dead clones in their tanks at the storage.
As for the revenge part, framing Bordon for murder was clearly part of the plan all along. he still hates him for the death of his wife and is very keen on being the best magician. The 2 go to extremes to get the credit.
Considering the exact science remark: I don't think that was a comment on the fact that it might stop working one day. It had to do with the progress and functionality of the machine at that point in time.