Wow, thanks for your comments! I agree that this seems like a way forward in trying to see if the idea of consciousness is worth salvaging (the way being to look for useful features).

I'm starting to think that the concept of consciousness lives or dies by the validity of the concepts of 'qualia' or 'sense of self', of both of which I already have some suspicion. It looks possible to me that 'sense of self' is pretty much a confused way of referring to a thing being good at leveraging its control over itself to effect changes, plus some epiphenomenal leftovers (possibly qualia). It looks like maybe this is similar to what you're getting at about self-modelling.