Advice on a JR pass please

We would welcome your advice on what to buy for the following itinerary - 28 days in Japan! Arrive April 22nd and leave May 19th.
Day 1-3 - Tokyo via Narita
Day 4-5 - Fujikawaguchiko
Day 6 - Nagoya
Days 7- 12 Kyoto
Day 13-14 - Osaka
Day 15-16 - Hiroshima (may go to Miyajima while there)
Days 17-19 - Port Uno/Naoshima/Port Uno
Days 20-23 - Takayama
Days 24-27 - Shinjuku
Day 28 - Fly out of Narita
I was thinking the 14 day pass maybe - to start while in Kyoto? to run out once we get back to Tokyo?? I don't want to waste the pass while spending 6 nights in Kyoto? I feel like it might not be worthwhile in the first week or so.
Thank you very much