FreeBSD 10 and ZFS: Methods for encrypting files

I’m in the process of setting up a FreeBSD 10 server on a KVM vserver.

I’m really new to FreeBSD in general (coming from Debian Linux).

I installed the system choosing ZFS with encrypted root volume and encrypted swap.

I chose this solution to protect my files (Emails, Filesharing, etc.) from outside access.

I then realized that I have to enter the passphrase on every bootup and the files (of course) are decrypted afterwards and available to everyone with access.

Is there a sane solution that I’m missing that would make it possible to encrypt only certain parts of the base system (to be able to boot without VNC and enter the passphrase via SSH)?

Is the whole idea of encrypting on a server stupid (since the volumes need to be decrypted for the services to work)?

Would encrypted jails be a solution or just increasing complexity?