Advice on itinerary and is the 21 day pass worth buying?

Hello Peter,

Yes, the fast majority of the places you plan to visit in Japan can be reached with the JR Pass. The only part that would need some additional transport is Kawaguchiko. I also am not familiar with Moriko, is that a small station? but for the rest yes, all is covered.

Yes, intercity travel can all be done with the Shinkansen and it is realistic to do this. Personally I think it is the best way to explore Japan. Trains rarely sell out and it is perfectly fine to make seat reservations on the day of travel, but still smart to do so one day ahead of time. Only during periods of high travel like Obon, Golden Week and the new year are seat reservations with 3-5 days ahead of travel needed.

Ryokan can be found all over the Japan, the best ''secret'' tip I can give you is read the reviews Japanese give them, as they understand the concept best and are very critical. So if locals say it is good, and it truly is so. A couple examples could be, stay the night at a Ryokan at Miyajima. In Onomichi, as this will be a bit less costly, Kyoto since it is the most famous (but pricy) place for Ryokan.

I see now that you mean Morioka instead of Moriko, visiting here is making really good use of the pass. That said, the city is not famous for tourism. I think other than exploring downtown and visiting the old castle grounds, there is not that much to do. I think you may enjoy it best if you know a local. I think many people go that direction to explore the local nature. A day trip to lake Tazawa is worth it too.

Kind regards,
Daniel