@Annmarie62 Be aware, though, that Airbnb only says profile photo, but doesn't require that it be a photo of their face- it could be a photo of their cat, a cartoon character, or a plate of spaghetti.
So if that's what it ends up being, tell the guest you require a clear photo of themselves.
As far as the profile from 2015, but no reviews, don't be shy to ask guests about things like that.
"Hi, XX, I noticed that you've had an Airbnb account since 2015, but not any reviews. I'm sure there's a reasonable explanation, but I'm curious as to why that is?"
I've had about 3 guests where that was the case. It was for various reasons, but all quite innocent. One had had 2 Airbnb stays but the hosts hadn't reviewed her, one joined planning a trip but never ended up being able to take the trip, one had always travelled with her husband in the past, and their reviews were under his profile. As they all turned out to be good guests, I had no reason to disbelieve them.