Virtualizing my entire home network

The biggest problem you will have is that remote desktop doesn't always work the greatest for multimedia purposes. In fact, without very specialized hardware and configuration, it can perform abysmally for playback of video. This is a problem with ANY remote desktop connection and not just Microsoft.

That being said, you can do what you are wanting to do AND get the performance for doing multimedia tasks, you just have to run the multimedia needs on the local machine instead of through the RDP service. For instance, you can set up a single remote desktop session host that allows each person to connect with a remote session to the SAME virtual machine. This gives everyone access to all the exact same work environment and software, and you purchase licensing based on the number of remote sessions users or remote client devices. The other option is to set up multiple virtual machines for people to directly access their own system. This allows them to customize the layout, the type of software, and you can customize the amount of resources depending upon the individual virtual machine's needs. This is called VDI. It can be a little more complex to set up and require a little more computing resources, but overall it's the closest to what you seem to be describing.

So, you can set up virtual machines (and sometimes even just duplicate your existing physical machine into a virtual machine hard drive file) and load that up into Hyper-V on your host server. Then using RDP you can remote access to these virtual machines. Without additional configuration or specific VDI implementations, this doesn't require a whole lot of additional cost, but the graphics performance is going to just be mediocre, but more than adequate for doing basic productivity tasks like browsing online or typing documents at 1080p. However, if you need better graphics performance you're going to have to set up a full VDI solution which supports graphics acceleration on each virtual machine, requires setting up additional VMs for things like connection broker, and can get more costly and complex obviously to do.

So, for the best performance (and cost) you can use remote desktop to access to your "standard" stuff on the Hyper-V server, and if you need to stream video, play back some sort of multimedia like a Blu-Ray or DVD, then use the local computer system to do so. You can use a more basic Windows desktop to do this and have access to Windows Remote Desktop features. A nice quality thin client can even do some multimedia functions, but they're much more stripped down and less flexible for a home environment and given the cost of a decent one you can pretty much just get a new basic Windows desktop instead and have the same or better performance.

One thing you may run into is limitations based on licensing. What version of Microsoft Server do you have running now? Server 2012 Standard gives licensing to run two instances of that same licensing on one physical host. If you're going to be virtualizing Windows 7/8 desktops then you just have to use one license of that OS for each VM of course.

Next, given that number of virtual machines running simultaneously, you should make sure that your storage subsystem not only has the capacity that you need but the performance as well. You also have to be careful with your network throughput because even if you have full gigabit network, a single gigabit line can easily get saturated to your server if all that virtual machine traffic is running through it. This means a server with several gigabit network ports is going to give you better flexibility and overall throughput. And finally, keep in mind the cost of licensing for your additional software as that can make a difference if you are considering a multi-VM desktop solution more like VDI, or a single VM session-based solution like Remote Desktop Session Host. With VDI you'd have to license each VM individually, including software like Microsoft Office, but with RDSH you only have to license the one VM which each person remotes to and is given an individual session.