Help with 18 days itinerary in September!

Hi!
I will be visiting Japan for the first time next month, from September 13 to October 1st, 2018. I am trying to make an itinerary that would allow me to experience the most of the country while trying not to overcharge it! Hoping and trying to balance my time between cities and countryside, a bit of nature and some of the more �gtraditional Japan�h (temples, shrines, etc), as well as modern architecture and art�c

Would greatly appreciate any feedback on my itinerary :

13/09_TOKYO (arrival early in the morning). Night in Tokyo
14/09_TOKYO. Night in Tokyo
15/09_NIKKO. Night in Tokyo
16/09_TOKYO to TAKAYAMA. Visit Takayama. Night in Takayama
17/09_TAKAYAMA - SHIRAKAWA-GO - KANAZAWA. Night in Takayama
18/09_ TAKAYAMA to KYOTO. Night in Kyoto
19/09_ KYOTO. Night in Kyoto
20/09_KYOTO. Night in Kyoto
21/09_KOYA-SAN. Night in Koya-San
22/09_KYOTO. Night in Kyoto
23/09_Day trip to NARA. Night in Kyoto.
24/09_KYOTO to HIROSHIMA. Night in Hiroshima or Miyajima
25/09_HIROSHIMA - MIYAJIMA. Night in Naoshima or Teshima.
26/09_NAOSHIMA and/or TESHIMA. Travel back to Tokyo. Night in Tokyo
27/09_TOKYO. Night in Tokyo
28/09_TOKYO to HAKONE. Visit HAKONE - Lake ASHI. Night in Hakone
29/09_HAKONE to TOKYO. Night in Tokyo
30/09_TOKYO. Night in Tokyo
01/10_OUTBOUND FLIGHT (morning)

1. Is this itinerary too dense and busy? Am i trying to see too much? I�fm thinking of skipping the trip to Takayama / Shirakawa-Go if its too much. Or is feasible spending only one night in the area instead of two? Would i be really missing out?

2. I really want to go to Hakone, Lake Ashi, try to catch a view and feel of Mount Fuji. I put it towards the end of the trip hoping the weather conditions might be a bit better in late September than mid-September. Does that make any difference? Should i just do it at the beginning instead of Takayama? Worth trying to hike it up?

3. Where would be the best to stay overnight while visiting Naoshima and Teshima? Are the two Island feasible in 1,5 days? (2 days, minus the time to get there and back to Hiroshima). I am an architect and am very interested in art so would love to be able not to skip those on my itinerary!

4. Is it enough time in Kyoto and Tokyo ?
Should I maybe skip Nara ? Very interested in seeing temples and shrines, but don�ft want to do too much to avoid an �goverload�h of temples into a short amount of time...

5. JR Rail PASS: I know that not all of these destinations are covered by the JR Pass, but couldn�ft really figure out which ones are and which aren�ft. Would appreciate any insight on what pass should i use and for which part of the trip, and where can�ft I use it / what other passes I should buy ?

I am looking to see what is the best order in which visiting all these places, if it is not too much and too packed�c this still need to be a vacation :) Any advice, recommendations and suggestions would be greatly appreciated! (Sorry for this long post!)

Thanks in advance!
Yael

See previous post.
https://www.japan-guide.com/forum/quereadisplay.html?0+164295