I claim that it is "conceivable" for there to be a universe whose psychophysical laws are such that only the collection of physical states comprising my brainstates are conscious, and the rest of you are all p-zombies.

Yes. I agree that it is conceivable.

Now then: I claim that by sheer miraculous coincidence, this universe that we are living in possesses the exact psychophysical laws described above (even though there is no way for my body typing this right now to know that), and hence I am the only one in the universe who actually experiences qualia. Also, I would say this even if we didn't live in such a universe.

Sure, and I claim that there is a teapot orbiting the sun. You're just being silly.