Itinerary for Dec and which rail pass.

Hi there! Will be super thankful if you can run through my itinerary and recommend which pass I should get.

My rough itinerary for the Japan trip in Dec for 5A2C (include one elderly) is as follow:

Day 1: Reach Tokyo Narita at 7am (will be taking Keisei Line to hotel as there isn't a need to transfer, as recommended by Hotel); Tokyo City (Tokyo Tower, Shrine and maybe Imperior Palace);

Q: Should we get Pasmo or Suica card OR the 48-hour subway pass, since we will spend Day 1 & 2 in Tokyo City Centre?

Day 2: Tokyo City (Shibuya, Shinjuku, Harajuku)

Day 3: Hakone or Kawaguchiko (for views of Mt Fuji) - understand that a bus at Shinjuku is much easier and faster and less hassle. Which would be easier for us? Also, if time permits, we will go Gotemba outlet, which is near Hakone

Day 4: Tsukiji market, then Yokohama (or anywhere nearby Tokyo that u recommend?)

This is where I am stuck

Day 5: Shinkansen to Sapporo (4 + 3.5hrs) OR direct 1.5 hour flight?

If I am taking Shinkansen, I will activate the 7-day JR pass on Day 4. If I am taking flight, then I should get JR East-South Hokkaido 7- day rail pass?

Day 6: Noboribetsu and Lake Toya (or are these too far and nothing much during winter as we are not driving)

Day 7: Asahiyama Zoo (understand there is a bus going there, means no need for any rail pass, or the rail pass covers buses), back to Sapporo for Sapporo White Illumination

Day 8: GAO Centre, Tomamu OR Takino Suzuran Park or anywhere you can recommend for a day of sled, snow tubbing and snow fun for the kids? I heard Tomamu is overrun by lots of Chinese tourists. We do not need to ski.

Day 9: Otaru

Day 10: Sapporo

Day 11: morning flight home

So if i get JR 7-day pass, i will activate on Day 4 and it ends on Day 10.

If I fly internally to Sapporo, I get the JR East 7-day pass and activate on Day 5 and it ends on Day 11? Or no need to even get JR East pass? Just buy tickets from station?

Can you recommend which is the most price-saving way for us? I know my kids wanna take Shinkansen, so if I do not get the JR Pass, means we cannot take any Shinkansen?

My current concern is really about which pass to get that benefits us most. Also, is my itinerary workable or way too packed? Or is there anything that you wanna recommend us to go? We are very open to suggestions. Just that it must not be too tiring for the elderly (a little difficulty in walking too much and too far); the two kids are 5 & 8 years old.

Appreciate your time and advise. Look forward to hearing from you.