Something came to mind while reading all of these ideas.
David already thinks hes better than us humans. Going by the whole we come from engineers thing and are basically the same, perhaps David thinks he is "above" them also.
Also if he jacked another ship, maybe he has engineer tissue to work with for these experiments. Who knows? Those things just sort of popped in my head while reading. Experimenting on Shaw is one thing, but to just use the flesh of beings whom seed worlds like they are livestock, that might piss off a God, if there is one in this universe.