Disclaimer: It may not be for all hosts; however, it will benefit the most. I have worked on the following responses over the year with constant tweaking and assistance from other hosts. You are welcome to save, edit, change grammar, and content based on your need.
(1) Profile with Fewer Verifications than you Require— (note: it is not meant to address the absence of photo until a reservation is confirmed), "Dear Guest Name, thank you for choosing my listing. I trust you are well. Airbnb is built around trust, and an easy way to establish trust is by providing information about yourself; this is true whether you are a host or a guest. The more complete a profile is filled out, the better chance you have of establishing trust with the other person. I encourage you to follow the guidelines of Airbnb profile setup. For instance, upload a recent photo of yourself, your work email (if any), your selfies and a copy of your government-issued ID uploaded to the platform. Completion of the verification process enables us to know who we are allowing in our home. Thank you for your support in the matter. I look forward to hosting you. I am available to answer any additional questions about my space."
Note: For the scenarios below start with, “Hi Guest Name, I trust you are doing well. Thank you for choosing my listing. Your inquiry deserves a thorough response so that every aspect is clear when the reservation is made." Followed by what fits best:
(2) Viewing Request before or after the Reservation is made—"Airbnb releases contact information for hosts and guests after a reservation is confirmed. Permitting a visit before a confirmed reservation as well as arrival date is breaking of Airbnb’s Terms of Service. It is important for me to follow Airbnb policies. I encourage you to review the contents of my listing, its description, and photos. Thank you for your support in the matter. I look forward to hosting you. I am available to answer any additional questions about my space."
(3) Reservation Made by Third Party (family member, friend, etc.)— "Per Airbnb policy, it is required that the reservation must be booked by the person who is going to stay at the listing. It is important for me to follow Airbnb policies. If it helps, consider referring your (insert relationship) to Airbnb directly from your dashboard by clicking "Invite Friends". By doing so, both of you might be eligible for a referral bonus. When your (insert relationship) is ready to become an Airbnb guest, please encourage them to follow Airbnb guidelines of profile set-up. For instance, upload a recent photo of themselves, work email (if any), their selfies and a copy of their government-issued ID uploaded to the platform. Airbnb is built around trust, and an easy way to establish trust is by providing information about yourself; this is true whether you are a host or a guest. The more complete a profile is filled out, the better chance you have of establishing trust with the other person. Completion of the verification process also enables me to know who I am letting in my home. Thank you for your support in the matter. I look forward to hosting (insert relationship). I am available to answer any additional questions about my space."