[zener79]

Actually there are a couple of things that I'd like to clarify:

1) There is no WordPress backend to maintain as it doesn't exists unless you turn it on in a temporary/hidden/virtual environment to make your changes. For the rest of the time it simply doesn't exists. No PHP, no MySql, nothing that can break. You don't even need to keep your installation updated if you don't want to.

2) The pages are not served from an S3 bucket but from a CDN with 20 edge server around the world. The bucket is only a "source of true" where the CDN loads the files when the "cache" is invalidated. This reduce the TTFB (Time to first byte) up to 10x from any location respect a traditional hosting service.

[snowwrestler]

I think you've identified the right problems--security, pain of maintenance, performance. I don't think you're solving in them in the best way, but don't let that stop you! Hope your business is successful.