Do the extraterrestrials know about the deep subconscious? Do they think they are so different from humans that they believe humans have a deep subconscious cut off from conscious awareness, but they themselves do not?

They are in ignorance about their own dilemma. They see the difference between themselves and humans as being that they have introduced a defect blocking part of the human mind, not differentiating it as a functional aspect present within themselves as a defect. So they view the mind as having two levels, the conscious self and the subconscious, and believe humans simply have lost more of the subconscious through the fragmentation and are not aware of the hazard it represents for themselves personally—that much goes on down below within their mind in the relentless attacks and bullying from spirit meddlers that has corrupted them so severely and plagued them for many millions of years now.