I think it's grammatically correct but the meaning is obscure. I would tend to turn it around: "You're reading about it, but do you really want to know about it?"

No, it’s not correct and your meaning isn’t clear. You can’t add “reading it” on to a question like this. You add the -ing form to describe what is going on while the main action occurs. “Entering the room, he saw that she had left.” I think it would also be wrong in Italian. I think the equivalent is “Non vuoi davvero saperlo, leggendolo?”

Yes