That just looks fine to me 
What you see is inductor behavior (dip down) and the after that the back EMF of the running motor.
0,6mA per output, uhmmmmmm But if you overload it it will simply get hot and release the magic smoke. But low RPM does not mean high current.
But in the introduction you mention PID but you skip over that in the details. But I think that is the most important detail