Tell us about yourself!
Finally, someone that realises the importance of detail. Many thanks for the time and effort you've put into this. This should be used as a benchmark for posting a project here.Do you really need that last emitter follower though?
Could you please explain your choice of values for the decoupling capacitor. As far as I can tell, the choice is based on the required cut-off frequency and the input impedance of the ADC input using 1/2πRC. Values of input impedance seem to vary from 10k to 100M from different sources. So, what did you consider in designing this circuit? What is the purpose of the 47nF cap?