please help to select tickets

We will be travelling in Honshu for three weeks in November. Our itinerary is as following:

Week 1 : Kii Peninsula travelling from Osaka to Kii Tanabe after a overnight stay in Osaka. Will cover part of Kumano Kodo trail and then to Koyasan from Hongu.

N.B: in Kumano Kodo I anticipate we might have to use some local bus, in case we would need to shorten the walking distance between starting point and the destinations and we are happy to buy short trip tickets separately.

Week 2 : Will be based in Kyoto and take day trips by trains and buses

Week 3: stay and walk along Kiso valley Nakasendo trail for four or five days and have to be back in Tokyo for a couple of days stay, for return flight home.

My query is do we need to buy a JR pass for economical reason to cover the whole itinerary or can we cover our proposed plan with the regional passes (eg Kansai pass Kansai through pass) or any other passes we are not aware of.
I am aware that the final week of our itinerary will not be covered by any of these above mentioned passes. Could you please advise what is the the most economical option for us. Please note we do not need to rush to Tokyo at our final leg of the trip. Therefore travelling by bus or slower train always remain an option.

I apologise in advance for many components of queries. Thank you for your patience.