For the pins : 
- VPROPI : nice for "big" analog signal without big sense resistor nor external OP-Amp
- sleep : not sure it is really usefull : when the robot is on, the motors will have to provide torque all the time. I think that bin is mainly usefull for machines always powered on but not used most of the time. I'm not planning to use it
- fault : it might be interesting (even in in case of a problem, the robot is probably already lost). I was planing to group all fault pin in between 1 to 4 GPIOs, just for the prototyping phase