No. An electric bike's motor provides extra power to cycle faster (or with less effort). All that Shift4Me does is shift gears so that you're always in a comfortable gear (ideal cadence).
Well, on most of them. It can be installed on any bicycle that has a one-way (spring-return) derailleur cable equipped bicycle. That includes bikes with a sprocket gear, most hubgears, be it electrical assist or non-electrical.
A Shift4Me is not for sale. You have to order the parts and build it yourself. Normally, the cost of parts should be around 150 euros/USD. Prices can vary on where you're located - especially the availability of 3D-print services.
That depends. You (or someone in your neighbourhood) is going to need skills in soldering electronic parts and standard bicycle mechanics. There is a detailed building manual so even with very few skills, patience and the will to learn-as-you-go-along, you'll be able to finish it successfully. When you have all the parts ready, building and installing should be finished in aaround two days.
No. All that has to be modified on your bike is the flow of the derailleur cable. In the worst case scenario (if your build fials and want to return your bike to normal) you'll just have to de-install the Shift4Me and re-install your regular derailleur cable
In the process of designing and testing, I have had a working Shift4Me coupled to the normal derailleur cable. But it turned out that the shifting was not as accurate is it should be. So: (yes) it can be done to have the Shift4Me "in parallel" to the manual gearing, but (no) I haven't been able to make it run as it should.
In the original build and with most bikes I've tried it on, the battery will last about 8 hours. If you run out of battery power while you're on the road, the servo will no longer be able to pull the cable. That means you'll be stuck in the gear you're in (probably the "loose cable" gear) until you get home. With most hubgears, that will be the lightest running gear. With all derailleur gears, it will be the heaviest gear.
Shift4Me is a comfort-improving gadget: by making sure you're in the right gear for a good cadence, the efficiency is improved. That means the rider will enjoy an efficient thus comfortable ride. BUT a lot of sporty bicyclists may not like that gears are being shifted at other times than they choose. The people that will benefit the most are the ones that don't manually shift their gears often enough to maintain a good cadence.
Yes, there are several parameters that can be set to fit your needs, cycling style and type of bicycle. They can be set by connecting the Shift4Me via usb to a computer running the Arduino software.