Are any of these actual debated questions? Outside of religious arguments I don't think anyone can question that (in order) the answers are
It doesn't need a why/It was the best tool our ancestors evolved for their niche
It comes from electrochemical reactions in your brain
Of course it isn't you die when you are killed, getting head injuries can change your personality/memories.
Since your brain exists in physical reality the question "can we run a perfect simulation of physics" is also exactly "can we compute conciousness". Since it's looking pretty good that we can run a simulation of reality at the level we work at it's also looking pretty good for that whole "mind" in a computer thing.