7 days in Japan, stationed in Kumagaya

Hello. My husband and I will be coming to Japan for 7 days. Our hotel is in Kumagaya (traveling for my husbands work) and where we will be staying. The hotel is just steps from Kumagaya station, thus this will be my main hub for travel. While he is working, I definitely plan to travel to and throughout Tokyo for a few days, maybe a day trip or two from Tokyo (for example Mt. Fuji/Hakone, Kamakura), and then possibly, if time permits, a 2 day/1 night stay in Kyoto. I wasn't sure if for these travels a JR pass would be worth it? Additionally, can you use the JR pass for travel from Narita to Kumagaya station? Trying to see what makes most sense without spending additional money if it is not beneficial. Thank you in advance!