Hi Tiberius. I'm new on this thread but I'd like to enter in.
You quoted Gen.1:26 "And God said, let us make man in our image, after our likeness.." It is my understanding that "image" in this case means: shape, form, likeness: one head, two arms, legs, feet, hands, etc. But this is the primary meaning. We are created as living souls; we are sentient beings; we can think, rationalize, have feelings, desires etc.
It is true we read in Col.1:14,15, "In whom we have redemption through his blood, even the forgiveness of sins: who is the image of the invisible God; the first born of every creature:" And He is called the "unseen, only God" in 1 Tim.1:17.
But I believe this from man's view point, for "no man has seen God at any time". Yet, if we would see God, it would be Christ Jesus.
And, when ever angels in the Bible are seen, they look like a man. Oh, they can be radiant and bright, or not.
IMO, Adam and Eve had minds and learned how to prune, keep and guard the garden, with God in human form, as their teacher. They must have known what death was, from plants and even animals dying. And I believe they knew much that was good, but probably not what was evil. So when the serpent said "you will not die. For God knows that when you eat of it your eyes will be opened, and you will be like God knowing good and evil;" Eve ate and so did Adam who was there.
All for now, Bick