Need a answer thats more then just no! lol

When you remove the pedals, you are no longer a 'motorized bicycle'... you are now a 'scooter' & fall under a whole different set of laws. (also, scooters aren't as fun!)

I do think there should be a way to hang a 1-was double sproket on the left side of the crank BB shaft to do the gear ratio changes on the way too left rear wheel sproket ,leaving the regular right side pedal set-up working as it should

Or for only a little more you can keep the pedals and shift gears with one of these Sick Bike Parts Shifter Kit

will it spin right way?

???,,,,,,,,,,,,,,,,,,,,,,,,,I think the shift kit is a wonderful invention,I was just thinking the above mentioned thought would act as the center gear ratio adjustment and allow the free flow of the chain or belt drive(over and under the chain stay)to the left side of the wheel on a direct drive,It could (and probibly should) be a high speed sealed bearing ,not a 1-way as said above.
It (depending on motor width)will probibly still need a J-shaft to move in(an inch or so) to the left side sproket plane,but would add the illusion of the motor cycle/bicycle driveline,be efficient and solve the narrow chain stays and frame altering for chain drives, and be compatible with the pedal arms.
The high speed bearing seems the best to me at this point ,sombody with tools can probibly wip this up in an afternoon