Right, and JoelKatz is only asking to verify information that he *already* knows and which is entirely public at this point.
That's not quite true. I would be asking them questions whose answer I know within a range but don't know for sure.
If there is anything about this asic machine that is truly a secret, it probably doesn't need to be disclosed in the exchange. He is merely asking to confirm that this group has the relevant know-how to manufacture such a machine (or even build a prototype).
That is essentially correct. There are certain thing you have to do in the process of designing, building, and testing an ASIC. The questions I would ask would be things they would definitely know. An example question might be "how many gates or equivalent does the ASIC have?" Or "what is the die size?"
Now, I don't know how many gates their ASIC has, but I can calculate how many it would have based on other information (such as the number of hashes and the clock speed). I can then check my gate count against theirs. Similarly, I can calculate the die size based on other information and check its consistency.
The value of their project is almost entirely in the fact that they have (assuming they're telling the truth) actually made masks and spun up a production process. The design is not secret -- we all know how it would be done. That is assuming their design is based on the FPGA miner. My first question would be to ensure we're on the same page as far as what I'm assuming about their design.