10 days in Japan

Hi.
My husband and I are going to Japan for 10 days. We will arrive to Narita airport and stay 3 nights In Tokyo. From the airport to the hotel we can take either the JR Narita express or the Limousine Bus.

From there we are traveling to Kawaguchi for 2 nights, Here I think the bus takes less time because it goes directly from Shinjuku to Kawaguchiko.

Then we are going to Kyoto. I think we will have to go back to Shinjuku station and take the shinkansen train (is that the best way to get to Kyoto?)
In Kyoto we are staying for 4 nights. My husband has a meeting and I have not yet a exact plan of what I am going to visit.

Then we will go 2 nights to Nara (Do not know yet how to go there).
From Nara we have to go to Kansai International Airport. How is the best way to get to the airport?

Should I buy the rail pass?

Thank you in advance for your help

Teresa