Tokyo & Hokkaido in Jun 2015

Hi, I would like to find out if I should get the JR National Pass for 14 days for 1 adult and 2 children.

My travel plans are as follows :-

Day 1 : Fly from Tokyo Narita to Sapporo. Travel via rail from CTS to JR Sapporo Station
Day 2 & 3 : Travel in Sapporo (using JR Pass ? )
Attractions @ Sapporo
i) Sapporo JR Tower Observatory T38
ii) Hokkaido Jingu
iii) Takino Suzuran Hillside National Park

Day 4 : Free Shuttle from Saporro to Furano provided by hotel
Travel in Lake Toya and Noboribetsu for sight seeing

Day 5 : 2 options
Otion A ) Travel by JP Rail from Lake Toya to Furano. Please advice if it is possible
Option B) Take free shuttle from Lake Toya to Sapporo and take rail fro Sapporo to Furano

Day 6 - 8 : Explore Furano and Biel

Day 9 :
Option A) Fly from asahikawa airport to Haneda aiport
Option B) take sleeper train from Furano to Tokyo ( i understand I can only book for Cassiopeia train when i'm arrive in Japan).

From Haneda, how do i travel to Tokyo Disneyland ?

Day 10 : travel from Tokyo disneyland to Hotel Sunroute Plaza Shinjuku
Explore Tokyo

Day 11 : Hotel to Narita Airport

I would appreciate your advice on
i) is it cost savings to buy JR PAss
ii) Travel from Lake Toya to Furano
iii) Travel from Furano to Tokyo via Cassiopeia train

Appreciate your prompt advice. thanks