Yeah thats one way to address the issue (or even using multiple emails), but you know what's even better than that?
Having competent customer support, that would be able to address situations like this. Esp. with the amount of people that are using these home automation services with "cloud" support, its only going to get worse the more integrated these services become.
My friend has had a similar situation with the good ol Yahoo eMail service, and after being on call waiting for 4hours, they told him they cannot help him, then hung up.
I also had a similar service, with my STEAM account, I emailed Valve, and within 45 min the account was restored.
Lol, I was 1/2 way through this email thinking I'd respond that the only one worse is valve... turnabout. I've never had them respond to me. I've got several tickets multi months outstanding.
It is possible they queue their client service based on how much money each client has spent. It is what I would do if I did not have time to get to everyone cost effectively.
Use the cryptography based 2FA (with Google Authenticator on your phone). SMS is too open to social engineering, and as a second factor might actually make your account less safe.
Not that I'm aware of. I think there's an element of "grass is always greener on the other side." When the NSA thing first came out, people were publicly talking about leaving for GMail for Fastmail, since Google showed up in the XKeyscore docs, just as people felt superior about their Androids when the Apple Foxconn scandal broken. But in all likelihood they suffer from many of the same problems; Fastmail (and the various Android manufacturers) are just smaller and don't attract the same negative attention.
I haven't had my account hijacked before with fastmail. But I have had to contact support and I was in touch with a real person in less than 30 minutes.
I have dealt with Fastmail support in the past, although it was regarding invoicing questions, not identity fraud. My experiences were fairly positive.