No, I looked for references in the bible of dead speaking and there are some there, so yes, the dead do speak. When my youngest daughter was a toddler she had an invisible friend and chatted constantly with the invisible kid. As she aged it stopped. Then, last year when she was 17 it was discovered she had a terratoma, a technical name for a deceased twin that she had absorbed before she was born. It had hair and teeth and flesh about the size of your fist lodged near her girly parts. She still remembers talking with her friend and recalls her name was Sandy. For some reason children are open to these things and as we age and logical reasoning is taught it fades away.
I think its just fine to ask Daniel questions if you want to. It wouldn't be traumatizing for him because if it were God wouldn't allow it to begin with. I would ask lots of questions.