Should I need JR Pass for my Itinerary?

Dear Daniel-san,

We'll be travelling to Japan for the first time from 16 th to 27th December, we'll arrive at Kansai Airport Osaka and depart from Narita Tokyo. My plan for the trip is likely:

16 Dec : Arrival at Kansai Airport (Osaka) at 09.30 AM
17 Dec : Osaka
18 Dec : to Kyoto (Day Trip), continue to Tokyo (evening)
19 Dec : Tokyo
20 Dec : Tokyo
21 Dec : Tokyo (morning), continue to Sapporo (evening)
22 Dec : Sapporo
23 Dec : Asahikawa (Day Trip)
24-25 Dec : Niseko (stay for 1 night)
25 Dec : Niseko (morning) / Sapporo (evening)
26 Dec : Sapporo (morning), return to Tokyo (afternoon)

With above itinerary, could you please advise should I use JR Pass 14 days? OR is there any better transportation method? since I also consider to use :
- Overnight bus for my Kyoto-Tokyo Trip (18 Dec) - Flying with ANA Round Trip for my Tokyo-Sapporo Trip (22 Dec morning) & Sapporo-Tokyo Trip (26 Dec evening)

Thanks