Actually, with a little clever engineering I can imagine e-planes actually becoming quite a bit safer than fuel-burning ones in an "out of power" scenario. If you run out of fuel at 10,000 feet, then you have the unenviable task of navigating an unpowered glider to a safe landing. If your batteries run out, you have the aerial equivalent of regenerative braking. As you descend, props could become effectively wind turbines, pumping a bit of charge back into the batteries. Not a whole lot, probably - but enough to give you powered manoeuvrability close to the ground, where it counts.
