I would still be worried about the domain. If my DNS provider messes up, I change to a new one and I am back within 72 hours (at most). If the mail provider me

I would still be worried about the domain. If my DNS provider messes up, I change to a new one and I am back within 72 hours (at most). If the mail provider messes up, I change to a new one and I am back within X hours (where X is the TTL set for the domain). If my webhost messes up, I am back within X hours (because I of course make offsite backups), etc. The only part where one needs a 100% reliable business partner is domain registration. And after hearing all the horror stories about Godaddy, I would not trust them, not even if I was wearing your methaphorical condom.