Hakone, Fuji Five Lakes and Nikko in December

We (me, my wife and 2 kids) will be visiting Tokyo mid December for 8 days. Me and my wife have visited most parts of Tokyo city on our previous trip. We enjoy natural sceneries and onsen. We have tentatively planned our itinerary as follows:
Day 1 (11 Dec): Arrive early & half day Tokyo tour
Day 2 (12 Dec) : Disney Sea
Day 3 (13 Dec) : Disney Sea
Day 4 (14 Dec) : Hakone
Day 5 (15 Dec) : Hakone
Day 6 (16 Dec) : Fuji Five Lakes
Day 7 (17 Dec) : Day trip to Nikko
Day 8 (18 Dec) : Tokyo

We are not sure about the followings:
1) We will buy the 3-day Fuji Hakone Pass and stay 2 nights in Hakone. Shall we tour Fuji FL on the 2nd day or the 3rd day after we check-out from our Hakone hotel?
2) If the scenery of Fuji FL is similar with Hakone, shall we skip Fuji FL and instead stay a night at Nikko?
3) During winter, is it worth while to travel up to the 5th station of Fujisan?
4) On Day 6, after reaching Shinjiku from Fuji FL by express bus, is it doable/advisable to buy the 2-day Nikko Free Pass ad travel straight to Nikko for an overnight stay there?
5) Hakone or Yumoto Nikko has more options/cheaper onsen ryokan?

Appreciate advice from everyone.

Thanks.

You could go to Nikko and your kids might enjoy Edo Mura theme park. The lake Chuzenji is pretty, and the areas around the main shrines is pretty.

Hi, I can't answer most of your questions but I don't think a day trip to Nikko is enough, there's so much to do so you might enjoy spending 2 days and a night there.