> always use your own domain so if your email service locks you out, you can move to another instantly.

What to do if your domain is taken away legally (e.g. via trademark dispute) or due to a random combination of unlucky factors is bought before you can extend it?

Besides what email do you specify when buying domains? Where do you host that email? How do you deal if that email locks you out?

I hope don't say "use me@example.com to register example.com" because that circle seems like a fun thing to solve in a pinch.