Oh, I like this argument a lot! I'd really, really prefer that all visions of dead parents on this show be unconscious projections of their children's fears and desires rather than actual voices from the beyond. That's just way, way too anvilly. (Though damn. If it's Clark's unconscious mind, he's a little full of himself. Symbol of peace and justice is anvilly coming from Jonathan, but really self-important if coming from Clark!)

And if that's your reading of the visions, I now better understand why you see Lex's vision of Lillian as being about accepting that he's becoming a vision. If it's all a projection of his subconscious mind, that would have to be the explanation.