Correct.... or volume.
A sphere with only a 10% reduction in diameter has a 27% reduction in volume. So a vehicle might be shortened far less than 30% in each dimension, yet reduce it's overall volume by 30%.
Yes, that as well.
Or the G3/E might have to pay more upfront since the large volume of cars means Tesla would need to build even more superchargers to service them. Busy superchargers are already getting clogged up with 16K cars on the road, what happens when there are 150K-300K+ cars on the road?
I doubt. The biggest cost is the initial deployment. Adding more terminals tends to be cheaper and easier then getting all the paperwork done and doing the initial wiring. The cost to scale the stations should be cheaper. Also, by the time the Gen III comes out, I expect more level 3 chargers will be put up. So there are 3 things to look at:
1) Tesla will most likely get the 5-10 minute charging working by then which means less need for more terminals.
2) If my hunch about 35kwh-40kwh is correct, it will be much easier as you can charge 2 Gen III for same amount as 1 Gen II
3) At 35kwh-40kwh even a 50kwh level 3 charger can charge you to full in around 40 minutes.