The maximum operating temperature range for the NRF51822-QFAB-R7 is -40°C to 85°C.
The NFC pins on the NRF51822-QFAB-R7 can be configured using the NFC peripheral in the Nordic Semiconductor's SDK. The NFC pins are multiplexed with other functions, so you need to configure the pinmux correctly.
The maximum current consumption of the NRF51822-QFAB-R7 is approximately 14mA in TX mode and 10mA in RX mode, depending on the frequency and transmission power.
Secure boot on the NRF51822-QFAB-R7 can be implemented using the Nordic Semiconductor's Secure Bootloader and the TrustZone-M security extension. You need to generate a secure boot image and flash it to the device.
The maximum data transfer rate of the NRF51822-QFAB-R7 is 2Mbps for Bluetooth Low Energy (BLE) and 424kbps for NFC.