As Cuno says, in the case of this board, the function is only gateway. The idea is to work on the development of different devices with I / O, and communicate using RF with the gateway. In this there is nothing new.
We decided not to use Zigbee or Zwave, because I think it is not ideal for IoT.
We are thinking of adding a esp8266 module for wifi, but to complement ethernet. Not to replace it.
Bottom side of the pcb does not have any component.
The cost of the components should be below the u$s 100.
For most devices that have no connection to the cloud directly, we are using PIC. I suppose it could be done also with MF but there are some factors, such as size and power consumption among others, and then we decided to use PIC.