I will look into the issue about adding server roles.
As for the rest, I'll put it on the wish list as a possibility. You're right that there are PowerShell commands to create, update, export/import etc on VMs. They wouldn't be terribly difficult to code in, but designing a decent interface for them is hard. I know that Microsoft's preferred method with VMs on Hyper-V is remote management, not console management, and I tend to agree with them.