I had both of these questions as well. I've always been confused about the word "spiritual," as some people seem to use it to mean "having feelings of awe or reverence that are cognitively similar to those expressed in religious worship" while others use it to mean "actually believing in spirits." I consider myself spiritual by the first definition, but not the second. On the survey, I described myself as "atheist but spiritual," but now I'm not sure this was the most accurate description, since it falsely implies that I believe in the supernatural.

As far as redistribution of wealth goes, I don't know what you should mark. I chose "Libertarian" because I am rather distrustful of centralized government, and redistribution of wealth generally depends on some sort of centralization. But I know very little about what sort of consequences redistribution of wealth would actually have, so my views on the subject are quite tentative. (I recall hearing somewhere that the Scandinavian countries scored highest on a survey of self-reported happiness, which would suggest that redistribution of wealth at least doesn't prevent a society from being largely happy. If anyone can confirm or deny this, I would much appreciate it.)

According to this Google result, "spiritual" in this context seems to allude to a kind of private, iconoclastic, mystical religion, as opposed to public, creedal, classical religions like most sects of Christianity. I hope that helps.

I took "spiritual" to mean in this context that you don't believe in ontologically basic mental entities, but still embrace feelings of wonder, majesty, euphoria, etc. typically associated with religions when contemplating/experiencing the natural world.

Do you not have a preference for low/high redistribution of wealth because you haven't studied enough economics, or because you have studied economics and haven't found a satisfying answer? (Alternatively, trying to answer this one question might just not be worth your time. If that's the case, I'd leave it blank. Or if you're otherwise choosing between two positions, flip a coin)

For 1, I took it as meaning having a belief in some form of soul, afterlife, or karma.

For 2. - you could fill out the political compass survey (it comes up later in the survey under "unreasonably long and complicated questions"). Alternatively you could pick the political labels that you think might apply to you and then choose one at random.

What does "spiritual" mean, in the context of "Atheist [but | and not] spiritual"?

I'd say, having the alief that, as IIRC someone on LW put it (I can't recall the exact wording and the search engine doesn't seem to help me), you are a timeless optimization process of which your current incarnation is a mere approximation.