I would imagine that this should work on distilled, RO, or milli-Q water. Water is a highly polar molecule, meaning that one end carries a partial positive charge and one end carries a partial negative charge. If you want to conduct electricity, you would want impurities because water does not ionize (If split by electrophoresis it will form non-ionic molecules H2 and O2). But for simple electrostatic attraction to move droplets around, I think that water would make a great candidate.

Marketing. The device is a bit slow. But it can be in principle operated this way, it is just slower. I did see newer devices that somehow are faster, and have similar capabilities.

Uh, she went to jail because her stuff didn't work. There is a bit of work between concept and working product delivered to the consumer.

You know nothing about the science behind anything.