Should i use a 7 day pass or 14 day pass or none at all?

Hi!

I have read many posts in this forum and i would like to thank everyone for being so helpful with the advice and feedback!

My boyfriend and i will be spending 2 weeks in Japan, we arrive on 3rd June, 2pm (Narita) and will be leaving on 17th June, 605pm (Narita). Because its our first time visiting Japan, we are a little confused about the JR pass and we're wondering which option is best for us. I have read many posts on JR pass i'm still unsure which is best for our planned itinerary because our itinerary includes rare places which most tourists usually exclude on their first time visit such as Teshima and Naoshima, as well as Sendai (which is up north).

My boyfriend is an architect and he's very interested in some landmarks and museums in those placesso that's why we included these places into our itinerary.

Any advice would be greatly appreciated.

Here's the planned route of travel around Japan:

Day 1: Narita > Tokyo
Day 2: Tokyo
Day 3 Tokyo
Day 4: Tokyo (leave early morning) > Hakone (Full day exploring Hakone, followed by an overnight stay in a Ryokan)
Day 5: Hakone (Finish Hakone by lunchtime) >Kyoto
Day 6: Kyoto
Day 7: Kyoto
Day 8: Kyoto (Day Trip to Nara)
Day 9: Kyoto > Osaka
Day 10: Osaka
Day 11: Osaka (leave early morning) > Uno Port (Explore Teshima & Naoshima Island before staying overnight at Uno Slope House)
Day 12: Continue exploring Teshima and Naoshima Islands in the morning before heading back to Tokyo
Day 13: Tokyo (Day trip to Sendai- my boyfriend wants to see the Sendai Mediatheque there)
Day 14: Tokyo
Day 15: Tokyo > Narita (Leave at 605pm)

So is the 7 day pass or 14 day pass more worth it? Or should we not opt for it at all?

Also, do let me know if the planned itinerary is too packed or how else it can be improved. I actually wanted to include Koyasan in but i took it out due to a fear of the lack of time.

Really really appreciate the help!!!! Thank you so much! :)

Love,
Elaine