I don't fly HPR, nor do I ever plan on flying motors the size you plan on selling. I have no skin in this game, so this is just my unsolicited observation of how communication has been going on between a vendor and his potential future customers: They are asking legitimate questions and expressing concerns, not because they want you to fail, but from my perspective, because they want you to succeed. And you respond by belittling them, calling them "negative", and doing nothing or providing no additional information/explanation to assuage the points they've brought up. From the beginning, you've only provided fantastic promises and claims with nothing concrete to back them up (other than some people providing vague stories of someone flying one or two of your motors years ago).
It would have been better to announce your venture here when you could provide a website, some products, or at the very least some photos to back up your claims. Something, anything!
I've never been in sales, but here, let me try providing a generic response that comes across better:
"Dear future customers. First of all, thank you for you enthusiastic interest in our future products. We understand your concerns, and we will have more details in the near future to gain your confidence that our products will perform to our high standards of quality and cost. We appreciate your patience while we get up and running, and look forward to doing business with you soon."