finally booked almost all the accomodation for my stay in japan during autumn season in nov.. all by airbnb.  2night in tokyo, 4nights in kyoto and 3nights in osaka.
checking through agoda and etc, hotel price in kyoto so much expensive compare to normal day..some at least cost 2 times more.

need some advices here
1. i m now still looking for an onsen ryokan in kawaguchiko which is toddler friendly, any recommendation? will stay there for 2 night.

2. the shinjuku to kawaguhiko bus, do we need to pay anything to reserve the bus ticket? is it possible that i can take an earlier bus if i reach shinjuku earlier (from narita)?

3. end of november, is it advisable to reserve seat for shinkansen (tokyo to kyoto)?

many thanks

Why not get in at Kansai Get out at Narita?  save more time.

Day 1 when you reach Osaka already 2pm. Half day gone If you get in at Narita
Day 5 are Tokyo
Hakone put on Day 6

If you put Hakone at Day 5,,,from Osaka to Hakone,,another 1/4 day gone again.
Your planning are bad......I give 3 / 10

Your Shinkansen ticket might expensive than the different price of Tokyo - KL vs Osaka - KL

5 times.