I would not describe the electric taxis as 'fairly rare' in Zermatt. Admittedly we were there during the peak summer season but we saw many electric taxis zipping around. It just means you still have to be observant when walking around this amazing car-free village.
 Peak Pass
"Note that the Gornegrat train is not included in summer lift passes."
On the last visit in Zermatt - July 2006 - we had a 3 days peak pass and it included also Gornegrat + the train from Tasch to Zermatt.