Please help decide between 14 and 21 day JR pass

Hello,

We are traveling to Japan for a 20 day stay in July. We are definitely purchasing a JR Pass, just not sure which one would work best, and whether we can get away with using a 14 day pass, since some travel on some train lines and buses won't be covered anyways. Could you please take a look at our itinerary and advise what's best, thanks!!!

3 adults, 3 children

June 30th Arrive in Narita International Airport 1:25 pm, travel to Tsurukawa Station for check in near by
July 1 explore Machida by foot
July 2 take Odakyu line into Tokyo Government Building
July 3 take Odakyu line into Tokyo
July 4, travel to Hirata Station, Nagano (prefer using bullet train through Matsumoto Station if needed)
July 5th explore Matsumoto castle area
July 6th travel to Tsumago to walk the Nakasendo trail
July 7th explore Matsumoto area
July 8th, travel to Anamizu Station
July 9th explore Suzu by foot
July 10th travel to Komaiko Station near Kanazawa
July 11th explore Kanazawa
July 12th travel to Mukaijima Station, Kyoto (prefer using bullet train)
July 13th explore Kyoto area by train, walking
July 14 explore Kyoto area by train, walking
July 15th travel to Kasai Station, Tokyo (prefer using bullet train to get to Tokyo)
July 16th DisneySea
July 17th Pokemon Center and surrounding area
July 18th Ueno Zoo
July 19th travel to Narita Airport from Kasai Station area for departure

The idea was to get a 14 day pass and start using it on July 4th through July 18, since the Odakyu line isn’t covered by the JR pass anyways, and we can just purchase roundtrip Narita Express tickets to travel from Narita into Tokyo on June 30th, and back to Narita on July 19th.

After looking at the itinerary above, what would you recommend? I would appreciate any help and advice you can give us, as well as any tips you might have for our trip. I know it’s rainy season, so we are prepared to juggle Zoo and Disney Sea on either of those 3 days.

Thank you,

Victoria