6Days Central Japan by Shinkansen & Self-Drive itinerary

Hi, 4 of us are going to Japan from Oct 21-26 / 6days trip to Central of Japan, appreciate it if you could take a look at our itinerary and advise:

Day 1. Arrive Tokyo about 14:40hours and follow to Nagano by Shinkansen.
Day 2. Nagano - Kurobe Alpine Route (Tateyama) / start from Nagano and end at Toyama (day trip)
Day 3.Toyama (intend to rent a car from Toyama) self-drive to Takayama & Shirakawa for 1 night
Day 4. Shirakawa - Kanazawa
Day 5. Kanazawa (intend to return car at Kanazawa)
Day 6.Kanazawa to Tokyo by Shinkansen in the morning and connect to Haneda airport for midnight flight

Do we need to book the seats in advance and how much will it cost for the Shinkansen ride ?
Also how should we make bookings for the Alpine route tickets or package??

your comment is much appreciated.