Why does the Play Store need access to NFC? In xPrivacy, I can see that the Play Store asks for getNfcAdapter. 

What does it need it for?
The Play Store app has two main features regarding NFC, both of which require the NFC permission.


It registers intent filters such that when you scan an NFC tag with a market:// link or a link to play.google.com, you get the Play Store app instead of a browser, the same way you would when you click such a link. This doesn't require calling the getNfcAdapter function, but it does use the same permission.
It uses Android Beam. If you look at an app's page in the Play Store app, then bring another Android device to NFC range, you can send that app link to the other device.