Hi @Aggie1,
The stop watch refers to the pre-approval. So yes, you do need to ask your questions when the enquiry comes in. I have found most guests want to book, so they are pretty responsive to questions. If you get someone who does not respond fairly quickly, it might be a good indicator of their communication style in general, so I would likely want to decline someone who does not respond quickly.
I think the company is pretty good at verifying that the people inquiring are actualy the people they say they are. This is not 100%, but still, the company is pretty good. What you will find more often, and what is annoying (and against the terms of use) is when someone, say Marge, wants to book for someone else, say her daughter Ann. You will know that Marge is Marge, but you will have no idea about Ann, who would be the one coming. Decline these bookings. You get no protection from the company if you accept someone into your home who did not book.
Sometimes you will get an inquiry, and they might not even tell you that it will be someone else. This is what the questions are for. Usually that info becomes clear, or at least it becomes clear that something is off while you are communicating. Again, decline.
You do not get penalized for declining an enquiry unless you decline many in a row. You do get penalized for booking someone and then cancelling, so definitely communicate first.