You're saying we don't even know what consciousness is.
Not in the least. I know what consciousness is because I am a consciousness. The need for a theory of consciousness is necessary to tie the concept to the material world, so that you can make statements like "a rock cannot be conscious, in principle".
I am saying that if you claim to have a problem, you have to be more specific about what your problem is and what might convince you that it is not a problem
What might convince me is a satisfactory theory of consciousness. Do I have to provide a full specification of what would be "satisfactory" just to recognize an ethical problem? If so there is hardly anything about which I could raise an ethical concern, since I'd perpetually be working on epistemic aesthetics until all necessary puzzles are solved. This is just in fact not how anyone operates. We proceed with vague concepts, heuristic criteria for satisfactoriness, incomplete theories, etc. To say that this should be disallowed unless you can unfold your theory's logical substructure in a kind of Principia Ethica is waaay more useless than interpreting ideas through partial theories.
Do I have to provide a full specification of what would be "satisfactory" just to recognize an ethical problem?
Not "full", but some, yes. Otherwise anyone can squint at anything and say "I think there is an ethical problem here. I can't quite put my finger on it, but my gut feeling ("visceral level") is that there is" -- and there is no adequate response to that.
This seems significant:
http://www.theguardian.com/science/2015/aug/18/first-almost-fully-formed-human-brain-grown-in-lab-researchers-claim