Short reply to your first question:
Car No. 6 is near the elevator,
and Car No. 7 is near the escalators.
Hokuriku Shinkansen Kagayaki and Hakutaka trains
connect Tōkyō and Kanazawa Stations.
When the train runs from Tōkyō to Kanazawa,
Car No. 1 is at the rear end,
and Car No. 12 is at the front end.
[Kanazawa Station]
The platforms are above the concourse.
When Shinkansen trains make a stop there,
Car No. 1 is near the north end of the platform.
Car No. 6 (the door which is closer to Car No. 7)
is near the elevator.
- Google StreetView
https://www.google.com/maps/@36.5778805,136.6481753,2a,90y,320.21h,72....Car No. 7 (the door which is closer to Car No. 8)
is near the escalators (up and down, one escalator each).
- Google StreetView
https://www.google.com/maps/@36.577705,136.648044,2a,90y,294.94h,80.29...[Tōkyō Station]
- Tokyo Station City: maps
http://www.tokyostationcity.com/en/information/pdf/stationyard_1fb1.pd...The platforms are above the concourses.
Tōkyō Station has two separate Shinkansen zones.
: JR-Central manages the Tōkaidō Shinkansen zone
(Tracks 14 to 19),
which is shown with the blue-and-white Shinkansen pictogram.
: JR-East manages the Tōhoku, Jōetsu and Hokuriku Shinkansen zone
(Tracks 20 to 23),
which is shown with the green-and-white Shinkansen pictogram.
The Tōhoku, Jōetsu and Hokuriku Shinkansen zone
has South and North concourses,
which are a little higher than the surroundings;
each has at least one slope near the staircase.
When Hokuriku Shinkansen trains make a stop there,
Car No. 1 is near the south end of the platform.
Car No. 7
is near the elevator connecting the south concourse and the platform.
Car No. 10
is near the elevator connecting the north concourse and the platform.
