Correct Way to Add Volume Licensing Keys to KMS Host Server for Windows 2012 and Windows 8

We have a Windows Server 2008 R2 server that is our KMS host. It is activating Office2010, Win2k8, WinVista, Win2k8r2, Win7 now. And it needs to keep doing that.

I installed http://support.microsoft.com/kb/2757817 so this KMS server will now be ready to activate Win8 and Win2012.

I am ready to run

1. slmgr.vbs /ipk XXXXX-YYYYY-ZZZZZ-AAAAA-BBBBB

from an elevated command prompt on the KMS server.

Then next (I think) I need to initialize/ready the new KMS key by issuing the

2. slmgr.vbs /ato

command.

So far, so good, but:

1. Please verify the two slmgr steps above. 
2. Does KB 2757817 allow a Windows Server 2008 R2 to also activate Office2013?
3. My license administrator provided me initialy with a Win8 volume license key. I asked about Win2012 and he then provided a different key. Do I use both?
4. Did the licensing architecture change? There used to be "A" "B" and "C" levels in Windows volume license keys to activate different versions of WinVista, Win7, Win2k8, Win2k8r2. Do those "A" "B" "C" groups still exist? We have a "B" level now. Do I need a Win8/Win2012 "B" key?
5. Is there a single key do I should use so that I can activate both Win8 and Win2012? Or do I use the two keys provided to me?
6. Initally we will have only 1 or 2 copies of Win8 and Win2012 test machines. These won't meet the minimum requirements for KMS. But if we have hundreds of Win7 and Win2k8r2 machines, does that mean, in aggregate, we can continue to use KMS to activate WinVista, Win7, Win8, Win2k8, Win2k8r2, and Win2012?
7. Will adding the Office2013 affect our ability to activate Office2010? Same question about minimal number of Office2013 installs while simultaneously activating hundreds of Office2010 - or do we need to use MAK licensing for Office2013 for now?
8. And finally, once installed how do I verify that the other existing activation keys are continuously available to my Office2010, Win2k8, WinVista, Win2k8r2, Win7 clients (what commands to use)? If something breaks, how do I go back to the way things were so Office2010, Win2k8, WinVista, Win2k8r2, Win7 continue to activate (what commands to use before as a backup, and after, to restore)?

As you can see, lots of questions. I searched for answers, but can't find any. Why is there not a simplified FAQ on this? Sorry if these are stupid questions. Microsoft licensing is too complex for mere mortals.