Everything here is one message or one email. Nothing needs a phone call, and nobody will ask you to reconsider.
Text it to any of them and all of them stop straight away, not just the one you texted. You get a single confirmation and nothing after it.
Every message and everything stored about you, in a file you can actually read.
The account, the conversations, and everything the four know about you. All of it goes.
Your conversations mention other people. That stays inside your account, is never used to build a picture of them, and is never connected to them if they use Teylo too.
They share the ordinary facts of your life so you are not repeating yourself. Anything you say is private to one of them stays with that one. That is enforced in the software, not by asking them nicely.