http://www.secsyst.com/ - They manage Jackal Creek.
I really don't like their security
Bluetooth/Wifi - People don't really leave this on (I know I don't). It just uses battery. So I'd have to pull my phone out anyway to turn it on surely?
No NFC - With Apple finally adding NFC then most phones going forward will have it I think? If still no NFC then I reckon you could still provide like a QR code where you can hold up your phone and they can scan, and then if that sucks you can resort to just typing in a code. In the end the whole purpose is just finding the simplest way to type in the code