I would have to conclude that as far as I currently know, I have no way of knowing who else is or isn't conscious. So solipsism would then be a possibility, but not a logical necessity.

True, but you can carry the reasoning one step further. The claim "other people are conscious" is a positive claim. As such, it requires positive evidence (unless it's logically necessary, which in this case it's not). If your concept of qualia/consciousness precludes the possibility of evidence, you'd be justified in rejecting the claim.

Er... Except that we're not conscious of it! I'd say that's pretty special - as long as we agree that "special" means "different" rather than "mysterious".

Fair enough.

We needed some kind of word to distinguish these components of conscious experience from the physical mechanisms of perception because there is a difference...

Well, it depends on what you mean by "perception". If you mean, for example, "light hitting my retina and producing a signal in my optic nerve", then yes, experience is different -- because the aforementioned process is a component of it. The overall process of experience involves your visual cortex, and ultimately your entire brain, and there's a lot more stuff that goes on in there.

...just like there's a difference between a software program and the physical processes that result in the program running.

Hmm, I don't know, is there such a difference ? As far as I understand, when Firefox is running, we can (plus or minus some engineering constraints) reduce its functionality down to the individual electrons inside the integrated circuits of my computer (plus or minus some quantum physics constraints). Where does the difference come in ?

...and there's a qualitative sense in which experience doesn't seem like it's even in-principle describable in terms of firing neurons.

I lack this sense, apparently :-(

If you told me that it was discovered that there's actually a region of the brain that's responsible for adding qualia to vision (pardoning the horrid implicit metaphor), I wouldn't feel like hardly anything had been explained.

As it happens, there's a real neurological phenomenon called "blindsight" which is similar to what you're describing. It's relatively well understood (AFAIK), and, in this specific case, we can indeed point to a specific region of the brain that causes it. So, at least in case of vision, we can actually map the presence or absence of conscious visual experience to a specific area of the brain. I suspect that there are scientists who are even now busily pursuing further explanations.

You seem to be taking as practically axiomatic that there's nothing significantly different about consciousness as compared to anything else, like gravity.

The word "axiomatic" is perhaps too strong of a word. I just don't think that it's possible to treat consciousness as being categorically different from other phenomena, such as gravity, while still maintaining a logically and epistemically (if that's a word) consistent, non-solipsistic worldview.

You can make sense of gravity as an outside observer, but you can't make sense of your own consciousness as an outside observer. [emphasis mine]

Ok, let me temporarily grant you this premise. What about the consciousness of other people ? Can I make sense of those consciousness as an outside observer ? If the answer is "no", then consciousness becomes totally mysterious, because I can only observe other people's consciousness from the outside. If the answer is "yes", then you end up saying, "my own consciousness is categorically different from anyone else's", which seems unlikely to be true, since you're just a regular human like the rest of us.

but I cannot fathom a comparable place to stand in order to be conscious of consciousness while not interacting with it.

I agree, but I don't think this means that you can't "make sense" of your consciousness regardless. In a way, this entire site is a toolkit for making sense of your own consciousness -- specifically, its biases -- and for using this understanding to alter it.

Removing consciousness is exactly the process that would turn a person into a p-zombie, yes? ... Quite the opposite, I'm pointing out that drunk and meditating people have a different kind of conscious experience.

Ah, ok, I get it, and I agree, but I'm still not sure how this relates to the point you're making. If anything, it offers tangential evidence against it -- because the existence of a relatively simple physical mechanism (such as alcohol) that can alter your consciousness points the way to reducing your own consciousness down to a collection of strictly physical interactions.