The concept of the basic linear discharge tube with the electrons and ions accelerating towards their respective electrodes is satisfying.

But what about the convoluted advertising tubes ? I checked today on one where the tube folded back (the middle of an " E " ) and turned through some 315 degrees (the top of an " A " .  Why is the movement of and force on the particles only a straight line between the two electodes. Is there, parhaps, a high resistance leader following all the way through the tube ? 

Water molecules are slightly polarised so they should line up in a strong electric field.  I was always taught that they form hexagonal structures when they freeze though.  Which of these effects is more powerful?  Does the water freeze with a different structure?  What happens if I subsequently remove the electric field?