Hushmail does so, but, beyond the issues you cited, there is the issue of crypto-code-served-by-your-host. They can be forced to backdoor the client JS code and

Hushmail does so, but, beyond the issues you cited, there is the issue of crypto-code-served-by-your-host. They can be forced to backdoor the client JS code and you wouldn't notice (this, btw, happened with Hushmail).