Controversial Topic Discussion

There is some small distinction, which you point out yourself "if it's manipulated correctly in the lab," between a blastocoel and the other types of potential life you describe. A blastocoel, left alone in its natural environment has a very good probability of developing into a human. This is not the case with any of the other potentials you listed. Skin, left alone, will always be skin. Sperm left alone will be dead sperm and will never develop into a human.