@ addicted2climbing,
If you have a FSA / Sram crankset you could have a 110 BCD , so a Shimano or aftermarket chainrings for Shimano would not work since they are most always 130 BCD
Contact FSA directly , they will sell you a new chainring with the correct BCD to match your Crank, ( When I called them their price was at par or even lower than other places )
In regards to your motor, I have a 201 RPM Version of the Q100c, I only get about 20 mph out of it in a 700c wheel , 22-23 max with no wind, flat ground , medium-large amount of effort from my legs.
So
even though you have the Q 128 , still I think you got sent the 328 rpm version.
I live in a hilly area, I have a 20 speed drive train ( 2 x 10 ) on my Road Bike with Q100c motor, I most always use at least 17-18 of those gears on each ride that is not completely flat.
Anyone who says they /or you only need a couple , are not using their legs and cadence correctly, and/or using too much power from the motor .
( sooner or later their knees are going to be suffering )