The one gap here, is that if Google closes down your email account you can still be dead in the water if you have any services that rely on that email. Such as email based 2-factor authentication, or any websites that you forgot your credentials for an need to rely on an emailed password reset.

You can mitigate this by having your own domain and host the email on Google Apps -- that way if they take away your access you just update your mx record to point to somewhere else. But you can also easily lose your domain name (due to malice or accident).

BTW, if an emergency does happen, anyone have a recommendation for a decent web email client that I can point my MX record to? Preferably one that has both hosted and self-hosted options. Or something that I can spin up easily on a cloud service such as AWS.