Pass: Tokyo - Hakone -Kawaguchiko

Dear all!
We plan a trip from Tokyo to Hakone (stop for 2 nights), from Hakone to Kawaguchiko (stop for two nights) and return to Tokyo.Thus, the entire route will be five days.
Q1: What kind of travel pass is best for us?
Q2: What is the best way to get from Hakone Gora to Kawaguchiko?

Thanks so much!

Q1: What kind of travel pass is best for us?

Fuji-Hakone Pass for 6,740 JPY (new price per April 2019, purchase in Odawara, valid for 3 calendar days) is the best you can get. Depends on your itinerary, you can get an extra pass (check if it pays off) like Omnibus pass.

https://www.japan-guide.com/e/e6905.html

Q2: What is the best way to get from Hakone Gora to Kawaguchiko?

From Gora, you can take Hakone Tozan Bus to Sengoku, then to Gotemba (Odakyu Hakone Highway Bus), then transfer to Kawaguchiko (Fujikyu Bus). It may take 3 to 4 hours including bus waiting time to get there, but everything is covered by Fuji-Hakone Pass.

"Fuji-Hakone Pass for 6,740 JPY (new price per April 2019, purchase in Odawara, valid for 3 calendar days) is the best you can get."
but in this case Fuji-Hakone Pass will not be valid during our stay in Kawaguchiko, since it is only valid for three days?

One way Ticket is best for you.

Yes, you may at best only use it for your first day in kawaguchiko. Or alternatively, you can just purchase Hakone Free Pass in Odawara for 4,600 JPY for 2 days then pay an extra 1,500 JPY to ride the Fujikyu Bus from Gotemba to Kawaguchiko. See which one can save you more money.

As for Kawaguchiko, I guess you can only pay fares separately or buy the passes that fit you the most (you can see which passes are available from the link from the previous post).