I would try to use bipolar (right term?) ADC and DAC so both positive and negative voltages are allowed. I can see the single-ended ADC/DAC is quite limited in its applications. Oh, add a shunt resistor near the ADC for crude current sensing. This definitely needs to be positive and negative.
Your mock up is nice but in case you make them you will need an external breadboard adapter for prototyping on a breadboard. Just my 2 cents.