Answers
There are no 2016 Volts here - Michigan didn't get Gen 2 until well after the 2017 rollout started.
Diesel is marginally more expensive per gallon than regular (here) and occasionally the prices invert - diesel is cheaper.
Cruze looks to be about 600 lbs lighter than a Volt. Hence less hp needed.
This car is right out the factory and the salesman was sitting next to me so I didn't do anything zesty with the loud pedal other than force the tranny to downshift just to get a feel of the smoothness of shifting.