About Batty..

1) five years before the time frame of the film

2) because he hated the man; he hated him for building him, not giving him a longer life, and possibly lying to him to save his skin

3) You sound like you're doing a paper on the film, but I'll answer anyway; it was his reflection and summation of his life and how he felt about it, and how he wanted more but wouldn't be able to get any more because he was essentially a "machine" built to serve for a specific purpose, and had an expiration date purposefully built into him ... possibly to keep the combat models from getting too experienced and too developed to the point of becoming real "super" humans.

Roy's incept date was January 8th, 2016: https://pbs.twimg.com/media/C1rLxpnUkAA5jj7.jpg

What was Batty's speech towards the end about?

Actually, Deckard's voiceover in the Theatrical Version gives an explanation about that speech. Basically it makes the point that Batty has seen some amazing things in his time ('things you people wouldn't believe') but that they will be lost forever because he is going to die. As the VO said, all Batty wanted was the same as all of us - more life. The speech helps you see that Batty is as much an individual as any human and that his death is as significant as any - these memories are going to die with him and they are unique to him. It's an incredibly powerful speech, probably the high point of the film.

Interestingly Roy originally kills Tyrell because the Tyrell we see in the movie was meant to be a replicant, and Roy could "sense" this. Tyrell had died of a disease a few years earlier and was frozen until they found a cure. Roy was meant to kill Tyrell, and say to JF "now take me to the real Tyrell". They went to another part of the Pyramid where Tyrell's body is in a huge cryogenic chamber. Roy loses it and destroys the frozen chamber and kills JF. They didn't film it because it was deemed too expensive at that point. You can read bout it here and see Syd Mead's original drawings of the chamber -

https://curiousconstructs.com/bladerunner/lost/BRL-Tyrell.html