Hey Mark, it's great to hear back from you -- and probably best that you waited. My thinking has evolved somewhat on this point.... I big influence was Graziano's "Rethinking Consciousness: A Scientific Theory of Subjective Experience" -- a great data-based theory of how subjectivity works in the human brain. I also published a short book -- called Living With Frankenstein, on Amazon -- I of course highly recommend it!
The crux is this division between "unconscious" and "conscious". I had a long chat with a brilliant philosopher who said to me "but blood pressure is information that my body has, clearly regulates... but I am not conscious of it. Machine information is like blood pressure... it is manipulated.... but there is consciousness going on". This was a great objection! And this is exactly the heart of your point, as I interpret it.
Inspired by Graziano, let's talk about a "schema", his Attention Schema Theory proposes that -- like the body schema (a cartoonish abstraction of bodily state that the brain uses to guide action and make decisions) the brain also has an attention schema -- a cartoonish abstraction of what you are paying attention to. We are well versed, not only in our own attention schema but also those of others -- that's how an athlete quickly determines where a competitor is headed on the field, etc etc. Graziano argues that this attention schema is the heart of the hard problem -- in order to say "there is something in me that has subjective experience" there must be first a schema -- an internal model of the me that's having subjective experience -- that motivates the speaking of the sentence.
Graziano is great -- I think his particular, rather narrow definition of consciousness would satisfy many people.... but personally I am still committed to the "bag of tricks", and if you look at say the Global Neuronal Workspace camp, you see that in neuroscience many many other things are also put under the "consciousness" umbrella. For example, many body schema things -- like knowing where your left hand is -- factor as consciousness for neuroscientists who analyze patients with brain lesions.
Now, as for the conscious/unconscious divide -- I propose that we use the existence of a self-schema (not necessarily attentional, bodily or otherwise.... some informational representation of self) as the criteria for the kind of subjective consciousness that you talk about [other forms of consciousness -- simple awareness, being awake instead of asleep, etc, are possible without a self-schema but the subjective experience kind of consciousness, for which there is also an unconscious requires it]. This is how we can distinguish between conscious and unconscious qualia thereby solving the hard problem.
With all of this groundwork I think we can speak plainly of the single cell. It definitely has unconscious experience, related to itself. But does it have qualia? This depends on how much self-information it has -- does it even have such a self-schema? Does it affect the whole organism in a global fashion? If so then that process is the qualia of the cell. I'm no microbiologist but I'd wager there is a bit of that going on, but it's so minor it's hard for us humans to think too much of it. There is "something that it's like" to be a cell but man it's really dim and not much of a like-ness at all. Single cells at some very low tier do have a very basic qualia.... but does it satisfy Graziano's criteria for modeling attention? Probably not. Is it at all relatable to human qualia? Not really. So it's perfectly fine for people to say "that's not a meaningful enough quale to count for me as qualia".
