Arduino Nano with gamma radiation sensor

I want to make the small electronic device, which is a symbiosis of Arduino Nano with gamma radiation sensor. The circuit diagram, the circuit board and sketches are open source. Before I will order parts and the PCB, I want to ask the community:

  1. Does this format seem to be in demand or at least interesting (when a extra functionality is added to the main Arduino board, without additional shields; plus this board is compatible with all available shields)?
  2. The main thing - take a look, please, are there any errors in the circuit diagram.

I will be extremely grateful for any adequate advices and recommendations.

Also posted at https://arduino.stackexchange.com/q/44511

I was advised that the capacitor C14 is connected incorrectly. It should be connected between R8 and PIN diodes.