JR Pass worth

Hi
My husband & I are travelling around Japan for 18 nights. Below is the itinerary
Nov 9-10 Arriving at Narita Airport 5.30 pm (stay at Narita hotel)
Hotel @ Haneda - for early flight the next day to Sapporo
Nov 11 - 12- 13 Sapporo city sightseeing & Otaru Canal
Nov 14 -15 Hakodate (city sightseeing & Mt Hakodate etc)
Nov 16 - 18 Sendai and possibly to Yamagata
Nov 19 - 20 Nagoya
Nov 21 -22 Hiroshima
Nov 23-24-25-26 Tokyo ( Shibuya/Asakusa/Ueno/Roponggi etc)

Please advise if 14 day JR Pass is sufficient and if it covers all those destinations .
I read that Nagoya - Hiroshima line is covered by Shinkansen Nozomi

Also, please advise how to go to Yamagata from Sendai, Is it better to stay overnight there rather than going back to Sendai?

Thank you

Fransisca