2. Azure does not guarantee that you keep your ip address by default. You should configure a cname if you use Azure Websites or get a reserved ip address, available with Cloud Services
Actually, I am supposed to have a fixed IP. And I have CNAMES configured. I will review to determine if there is some other way I can set this up, but my issue is that I would never allow my products to be offline for hours without notifying my customers.
First, I am really sorry about the impact the incident had on your service. Specifically, for your changing IP, are you currently using the reserved IP feature. You can reserve both your external IP and your internal IP.