A:AnswerNo it doesn't, Playstation controllers don't have rechargeable battery packs you can switch out. You plug them in to charge them and you can charge them and play at the same time.
A:AnswerNo, it only covers 2 years from the date of purchase, it's usually better than manufacturer warranties in the sense that they provide enhanced coverage like accidental damage.
A:AnswerFor the PS3, pair it by connecting it via usb cable.
(https://www.nacongaming.com/en-US/blog/ps5-controller-ps3)
For PS4, you will need to purchase a bluetooth adapter. I prefer 8 bit do for connecting the PS5 dualsense to my switch. I would think that it should also work with connecting a PS5 dualsense to a PS4.
You can also use Remote Play for PS4, but I world imagine that would be a lot of lag.
