21 days trip

Hi there,

Me and my wife are travelling to Japan from February 26th to March 17th 2016,and this is our plan:

26/2 arriving in Tokyo Narita
27/2 Tokyo
28/2 Tokyo
29/2 Tokyo
01/3 Tokyo to Nikko
02/3 Nikko
03/3 Nikko to Minakami
04/3 Minakami and around(Takaragawa Onsen)
05/3 Minakami to Kanazawa
06/3 Kanazawa
07/3 Kanazawa to Magome (Nakatsugawa)
08/3 Magome to Kyoto
09/3 Kyoto
10/3 Kyoto
11/3 Kyoto to Himeji and back to Kyoto
12/3 Kyoto to Nara
13/3 Nara
14/3 Nara to Kyoto
15/3 Kyoto (maybe a day trip to Hiroshima or Koyasan)
16/3 Kyoto to Tokyo
17/3 Leaving Japan from Tokyo Narita.

Do you think the best option is to buy the 21 days JRPass?I was thinking about the 14 days because the first 3 full days in Tokyo but at the same time I need to buy twice the transfer from and to the airport,and the first leg of trip to Nikko too???Do you have any other suggestion?

Thank you very much for your help,
Dani