Copy-and-paste the relevant part of AirBnB's explanation of how Pre-Approvals work and send it to Guest 1. If they continue to harangue you, flag their messages to AirBnB and then ignore them. Don't respond in any way after that. On the plus side, no matter how angry the requestor is, they can't leave any negative reviews or comments on your listing.
I don't much like pre-approval requests, but when I receive one, I first send a message asking that the requestor read our House Rules AND our Cancellation Policy, and that they then confirm that they have no problem with either. Only if they follow up with an affirmative response do I consider approving their pre-approval request. I much prefer people who request a booking rather than a pre-approval. Most pre-approval people turn out to be window-shoppers, and only a small percentage actually end up booking.
If I DO accept a pre-approval, I also then send the requestor a message reminding them that the dates are NOT locked out and that the pre-approval lasts only 24 hours in any case. (I don't think that most pre-approval requestors have ANY idea how pre-approvals work.)
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