2. Communicate with the business through some other means (all local businesses I deal with have a phone), and if they don't provide one, then stop doing business there, too, and find a way to tell them why.
3. If your friends won't communicate with you simply because you won't use a Facebook-owned communication channel, then I have bad news for you: They might not really be great friends.
Sorry to be rude, but this idea that "you don't have a choice to use Facebook properties" is ridiculous. We all have a choice. I haven't used Facebook for close to 10 years now, and I never signed up for any of their other properties like Instagram and WhatsApp. I had an Oculus and stopped using it when the Facebook purchase happened. You do have a choice.