Justin is on the right track by aggressively researching torque-sensors and staying in front of the pack by making sure ebikes.ca / Grin-tech has in-house expertise. When riders have the opportunity to try out several different types of E-bikes, the pedelec E-bikes that use a smooth and seamless power delivery torque-sensor (rather than the slightly cheaper cadence sensor), is frequently cited as a smooth and trouble-free way to ride.
Some customers actually prefer to keep their hands free, rather than use a hand-throttle.
As far as the frame, few people will pay a much higher price for a near identical looking frame that has a quality level that looks only slightly lower than the actual high-end products from a well-regarded manufacturer. I call it the "WalMart-ification" of products.
I recently found a China export frame that is almost identical to the Electra Townie...why innovate when it's easier to just wait for something to catch on, and then copy it?
If you want to make 10 custom CroMo frames to start off a new E-bike business, look at Costa Rica. At least that way you can build up a business for a year or so before someone in China starts copying your idea (if there truly are any new ideas in E-bike frames).