I think #2 risk being incoherent unless you define things very carefully.

"Illusion" ordinarily means there's someone with a subjective experience which creates incorrect beliefs about the world. E.g. I drive on a highway in summer, I see reflections on the road, I momentarily believe there is standing water, but it's an illusion. What does it mean for the basis of subjective experience to be illusory? Who experiences the illusion?

> Pain isn't a real thing any more than an IEEE float is a real thing. A circuit flips bits and an LED shows a number. A set of neurons fire in a pattern and the word "Ow!" comes out of someone's mouth.

But we don't think the circuit has an experience of being on or off. And we _do_ think there's a difference between nerve impulses we're unaware of (e.g. your enteric nervous system most of the time) and ones we are aware of (saying "ow"). Declaring it to be "not any more real" than the led case doesn't explain the difference between nervous system behavior which does or doesn't rise to the level of conscious awareness.

Agreed! The difficulty with consciousness is that there is no observable effect to distinguish between, say, actual pain and simulation of pain (acting like you are in pain).

And I don't think I have a good handle (much less a coherent definition) on what it means for consciousness to be an illusion. What I think it means is that the process that is getting signals about the environment, and making decisions about what to do, is getting a signal that it is in pain. The signal causes the process to alter its behavior, and one of its behaviors is that when it introspects, it notices that it is in pain. The introspection (how am I feeling) is just a data processing loop, but that process, which is responsible for tracking how its feeling, is in the pain state.

There's a lot of hand waving here, which is why this is the Hard Problem of Consciousness and why this paper has not solved it.