Hi @Morris2 Booking as a "gift for a friend" is a third party booking and not allowed. I'm assuming the person who is booking for his/her friend will not be one of the people staying. I would decline the booking. You could also flag the profile, but it could just be an honest mistake & the person doesn't know 3rd party bookings aren't allowed & might change that when this is pointed out to him/her.
All communication must be done through Airbnb - this is for your protection so there is a written record should you need to involve Airbnb later. I wouldn't necessarily decline the booking because of that request, but would explain & insist communication stay on the Airbnb format.
Change of check-in date request with no reason given - I'm not sure. Most people are happy to explain why when they request any changes to the booking request.
If these 3 things are all occurring with the same person, I'd probably decline the request for reasons of not being comfortable with this guest. A "3 strikes & you're out" type of deal. Hope that helps! Karen