It would be an easy bike into Moab as it is 7 miles (if memory is correct) and all down hill. They have a great bike path most of the way now too. The return trip will be a bit rougher, but the e-bike will help there.
Arches is pretty close, although a steep incline at the entrance as well. Willow Springs road itself leads all the way into the center of the park, if you are up for the bumpy ride.