Ah! Welll.... that could be your problem.
Non-genuine OS is the WORST thing you can do. Why? Because they are usually hack spyware and viruses embedded at the OS level (rootkit style), meaning that no antivirus or security software can detect them, as the your security software sees it as if it part of Windows.
So it could be spreading, using Windows 8 sync malware to your Surface Pro 2. That explain the high system usage on power saving, and the the wireless activity when not doing anything.
I would refresh Windows 8 (hopefully that;s not infected), and not setup SkyDrive sync. See if your problem is solved.
Note that if you are in engineering or computer science, you can get Windows 8 for free from your school which could be registered to Microsoft MSNDAA/DreamSpark Premium, if not, you get to enjoy a nice discount on Win8 from the Microsoft online store.