The reason you are feeling a slight hesitation when the gas engine starts is due to the fact that for a moment the clutch that connects the engine and transmission is engaging. This system uses a dry clutch and computer controlled hydraulic operating system, just like a manual transmission. As you log a few more miles on the car I would think it might break in a little more. In a manual transmission you would use the clutch to do far more work than the hybrid system would and it may take a little time to smooth itself out, but you will more likely than not always notice it. Being a larger engine that lets you know it is running it will not be like driving a typical hybrid in some cases.
As far as maintenance and repair potential of the system it should be quite low. There are many new parts in this vehicle but very few moving components, and almost any repair would be component replacement. The fault detection logic built into these cars takes a good amount of guess work out of most faults.
The AC motor actually starts the engine in all cases on these cars. It also powers the wheels and generates energy when "braking" the vehicle.