Question: There are many questions in philosophy of the following kind:

* Does my friend have a soul, or is my friend a zombie?
* Is the mind separate from the body, or is it the same?
* Where does the universe come from?

These questions have the property that, whatever the hypothetical answer would be, every one of your perceptions of the world is *exactly the same*.

It is a central tenet of Carnap and the positivists that one should consider such questions as meaningless, as an abuse of language. This position answers or moots most of the questions on this site. Positivism was accepted for a while in philosophy, but no longer. I am shocked by this.

Is it still considered correct that a question with no perceptible difference one way or another (like, "Are you a zombie?") is inherently meaningless? Why would anyone assign meaning to such a question?

Answer: 
> 
> These questions have the property that, whatever the hypothetical answer would be, every one of your perceptions of **the world** is exactly the same.
> 
> 
> 

(emphasis mine).

You have imported an assumption here that, I think, explains why all of your examples are problematic.

What precisely do you mean by *the world*? If souls are real, and they (we) exist after death, does *the world* include the post-death environment of the soul, or not? If no, why do you privilege existence-as-soul-plus-corporeal-physical-form above existence-as-soul-in-post-death-environment? If yes, is it *necessarily* true that you have to find evidence pre-death, or can you wait until post-death to make the call?

So I think these are sensible questions to ask, even if, after a long detour that requires one to rethink one's epistemology, one concludes that the answers are, "no zombies or the question is meaningless; the mind is the same as the body or the question is meaningless; the origin of the universe is an insensible question unless you're redefining universe". You don't just (or many people do not) end up there intuitively, so the questions are reasonable to ask even if at the end you conclude, "Well, that was all just confused, wasn't it?"
**"no perceptible difference one way or another"**

To the senses, "no perceptible difference". To the intellect? **Profound** perceptible differences!

Nothing to be shocked about.