Hi Tricia,
Yes, a 7 day pass will serve you nicely here and you can start using it from Narita to Ikebukuro, taking about 90 minutes. Please be aware though that the Pass can't take you everywhere - for Takayama/Shirakawa-go you'll need other transport, likewise withing Tateyama. BTW make sure you are going to Tatayama on or after April 16th, otherwise it will be closed. Along with Shirakawa-go you also might go see Gokayama. The former you can see in just only a couple of hours. For Kanazawa, be sure to see the Kenrokuen Garden - many say it's the finest traditional garden in Japan.
For your time in Tokyo, you can also use a 3 day subway pass to save money:
http://www.tokyometro.jp/en/ticket/value/travel/index.html#anc03
There is also a cheap 1000 yen bus from Tokyo to Narita, since your pass will have expired:
http://accessnarita.jp/en/home/
These other links have good info you should look through:
http://www.japan-guide.com/e/e5900.html
http://www.japan-guide.com/e/e5950.html
http://www.japan-guide.com/e/e7550.html
http://www.japan-guide.com/e/e6030.html