simply run cmd.exe as admin and copy/paste the command there http://superuser.com/questions/497252/how-to-access-the-administrator-command-prompt-in-windows-8 http://windows.microsoft.com/en-US/windows7/How-do-I-run-an-application-once-with-a-full-administrator-access-token
the cpu usage comes from the nVIDIA driver. Please try a different one and look if this improves it. Also try to put the GPU into a different PCIe slot, if this is possible.
finally it is there: Windows 8 Release Preview VS for Windows 8.1.1 http://misaki2009.deviantart.com/art/Windows-8-Release-Preview-VS-for-Windows-8-1-1-459861480
the CPU usage still comes IP related services/programs (IPHLPAPI.DLL!NetioAddressChangeCallBack). The AddressChangeCallBack shows me that this is code which is executed after the IP changes. I see you have 29 Ipv6 addresses assigned to the Intel® Dual Band Wireless-AC 7260. Do you really need them all?
I also run Win8 on my laptop, but I hate the WPA.exe. I still use the old xperfivew. But for an overview the XML is fantastic. Share the ETL, so that I can take a look at it
the trace shows that you copy user profiles data during logoff (userenv.dll!CopyProfileDirectoryEx2, userenv.dll!RecurseDirectory which enums all files in the profile). This runs a long time and causes the slowdown.
The cpu usage still comes from IP operations (IPHLPAPI.DLL!NetioAddressChangeCallBack, WSDApi.dll!CWSDInterfaceTable::IsSameAddressList). Stop some of the Network related tools like ZeroConfigService and look what happens.