Is a 14 days JR Pass possible for this plan ?

I am deciding whether I should get the 14 days pass and if I do, hope to cover more places; please advise whether all of these places are possible.
Day 1(Oct 7) - Arrive Osaka Kansai Airport 7pm
Day 15(Oct 21) - depart Osaka Kansai Airport 11.30pm

I must be at Takayama on 3rd & 4th day, all other places fexible.
I wish to cover Osaka(no visit)- Hiroshima(1n) - Kobe - Nagoya(1n) - Gero or Kinosaki Onsen(1n) - Takayama(2n)) - Shirakawa-go - Kanazawa - Kiso Valley(1n) - Otaru - Asashikawa Onsen(1n) & or Sounkyo(1n) Onsen - Sapporo(1n) - Noberibetsu Onsen(1n) - Toya - Hakodate(1n) - Aomori - Yamagata(Dewa Sanzan)(1n) - Nikko(1n) - Tokyo(1n) - Osaka.

Is this possibe ? I will visit Kyoto & Osaka before that & I have visit most of Tokyo before. If this is possible, I will start to check for train times to finalize it.
My biggest concern is am I too late to catch the autumn foliage at its peak by around Oct 12 - Oct 13 in October ? If the peak is already over, I may skip Hokkaido this trip and put all the 15 days just in Honshu.
Thank you in advance and any advise will be much appreciated.

I think it is impossible to do unless you incorporate one domestic flight. But even then it would be an extremely busy itinerary.

For example:

2: Kanazawa - Shirakawago
3: Takayama
4: Takayama
5: Gero
6: Kiso
7: Nagoya
8: Kobe, Hiroshima
9: Hiroshima (fly to Sapporo)
10: Sapporo
11: Otaru
12: Asahidake Onsen
13: Noboribetsu
14: Toya - Hakodate
15: Aomori
16: Dewa Sanzan
17: Dewa Sanzan, Nikko
18: Nikko
19: Tokyo
20: Osaka

Unless you enjoy a very fast travel pace, I strongly recommend to drop some of the destinations (or add some days).