Nick_Pyner:
If you want a device to behave like and HC-05, get an HC-05.
If you want a device like an NRF, get a BLE device.If you cannot understand the difference, it might be time to re-examine your preference for the NRF.
Both have bluetooth in their name, and run on 2.4Ghz, but that is about all they have in common
Some comment on basic BLE: HM-10 Bluetooth 4 BLE Modules – Martyn Currey
I need the NRF5 in specific because you can program it easily and implement along the bluetooth other stuff,
Any way, are you sure there is no way to make the connection more secure with something like a pin code or a password before you connect to it?