1-4 is simply providing them with a copy of the instructions. 5, 6, 8 and 9 are incredibly obvious questions that should have been answered during the development. 7 is surely something you know just from the business end of things.

I have no idea what FMVSS is but that there are regulations here should be obvious, no doubt this would be something you'd become aware of after a little bit of research. As a consequence you should have an answer to that. This covers 10-12.

13 and 14 he should have known at the top of his head. 15 it seems you could just say you've nothing to add or drop whatever else you have on hand.

Nothing about this strikes me as unusual, unexpected or hard to answer. There is no way this is the reason Holtz gave up unless the product is a complete failure, he hasn't run any safety tests whatsoever or he's using this as an excuse to cover up something else.