Hi lostone,
I can't answer your first question as I am not co-conscious as of yet. However, I can tell you that T has said before that some parts of my brain do know other parts exist and some don't know any other part exists. She has also said that some parts know of some parts, but not all.

I think it just depends on the person? Just remember, you are not crazy. Dissociation comes from needing to protect oneself from unacceptable things. It's a coping mechanism and one can learn other coping skills to help dissociate less. Hang in there.