All of your questions are easily answered in public and EDGAR filings at the local, state and federal levels. Further proof is not reasonable. When you suggest a walk through with camera, that is a completely unreasonable request since I doubt any corporation with sensitive proprietary production knowledge would agree to such a thing from any investor.
Building permits are accessible, use licenses are public filings, FDA filings for the INDA can be accessed, and finally, when stated in EDGAR compliant quarterly reports and material events, officers are fully liable for any misleading information.
This isn't a paper mill startup with a novel way of boiling fiber.