These are a few different questions, so I'll do one at a time.
We have "relative" reality and "ultimate" reality. According to Buddhism, and according to science, there's no ultimate reality of this "I". Science says even the body is just full of air, empty space, atoms, etc. This table doesn't exist. (Steve hits the table) Even though I hit it, I know it exists, but scientists will tell me it doesn't really exist, its just all atoms. In "ultimate reality", that's fine and might be true - it doesn't exist. In "relative reality" the table exists and so do I. In order to communicate, it's good to use relative reality.
Many years ago, we had a person who did not want to use relative reality. The word "I" was not in their vocabulary, neither were the words "me/mine". "This body wants to eat." "This body now wants to go to sleep." This was how the person talked. He was a bit nutty, unfortunately, but in absolutely no way at all was he going to talk about "I".
He was visiting us on our farm in Australia, staying in one area in a tent. That night he got angry, the owls were making a lot of noise. He took a stick and banged on a 44-gallon metal drum so the owls would go away, and he could sleep. We heard the beating, but it was about half a kilometer away from where our house was, in the night, so we waited until the morning to go down and check him out.
When we asked him what had happened, he said something like: "The owls were making too much noise, so this body went and took a stick; and the body hit it on the can to drive the owls away." He couldn't admit that he himself had aversion in the mind. He, himself, couldn't handle the fact that the owls were making noise, and so on. This whole way of talking was a denial of his work that he did not understand.
When we actually say: "I have anger", or, "anger exists right here, in me" - not just in "the body", but "in me". Whatever we think of "me", because it's behind our eyes, right? Where do we think the "me" is? It's behind our eyes. (For people who are blind, it's not behind the eyes, its more in the hands and ears), but we think there's an "I" there. So, that's relative reality. We don't want to deny that by using words that then end up being very foolish. So, we don't think its possible to throw away the words "I", "me" and "mine". In fact, it's really negative to do so, and it's much more beneficial to acknowledge that, "I" have work to do.