Hey! I feel like ensuring you clarify you'll only shut down an account if they break the rules you set out is a really good practice and there are examples, like FastMail's, you could borrow from. I know the standard boilerplate is to give a service the right to do whatever it wants, but as a small indie service operator you can be better than the fairly standard! ;)

Your service running itself is a good idea for avoiding you doing a lot of work, but if you got hit by a bus it is likely someone would shut off your credit cards that pay for services your services depends on and even if it's a box in your house it will end up unplugged. I'd strongly advise some business continuity involving a very trusted friend or family member who can be your second in managing the service at minimum, who has access to everything and knows what to do already.

I hope you don't take my comments as too much of a knock, what you're building is hard and worthwhile, and I wish you success with it. I'm on FastMail but that doesn't mean I always will be, and I like to have good options by good people.