Certainly an action-packed trip, with a lot of rushing about, hither and yon c. A few thoughts, for what theyfre worth -
Are you planning on getting a 14 day JR Pass? I assume youfve checked that itfs worthwhile?
March 3 - if this is a day trip to Hakone, why are you getting a 2 day pass?
March 6 - obviously personal preference but it has always been a complete mystery to me why people want to go and see monkeys (even snow monkeys) - seen the photos, seen the videos, donft ever need to go and see them in person (particularly given everything else to see and do in Japan) c. obviously YMMV.
March 7 - very little time in Kanazawa - itfs easily worth a couple of days. Donft miss the superb Kenrokuen Gardens, arguably one of the best (if not the best) in Japan.https://www.japan-guide.com/e/e4200.html
March 8 - as I just commented in another thread, donft bother with Shirakawa-go \ save yourself the hassle and just go to Hida no Sato when youfre in Takayama.https://www.japan-guide.com/e/e5901.html
March 11 - Arashiyama \ most people go to see the Bamboo Grove and Tenryu-ji and the generally-overlooked (fortunately for the rest of us) Okochi-sanso. Therefs also a monkey park c..https://www.insidekyoto.com/okochi-sanso-villa-arashiyamahttps://johnliddlephotography.com/2018/04/22/ohkochi-sanso-villa-kyoto...
March 12 - what are you planning on doing in Osaka? I would do a day trip to Himeji and, on the way back to Kyoto, stop in Dotonbori in Osaka in the late afternoon/evening for dinner.https://www.japan-guide.com/e/e3501.html
March 13 - Koyasan is rather time-consuming to get to, so is better suited to an overnight temple stay.
March 16 - The timetable says "The operation of SL Hitoyoshi will be suspended from November 5 until the middle of March.h It appears that it resumed on March 16 this year so will presumably be operating again by March 16 next year?
For my taste, you have way too much rushing around and not enough time to stop and enjoy where you're visiting but hopefully you'll have a good trip.