Options

Hi, I will travel with my family in July/August for 2 weeks (exactly 14 days in Japan). We plan to stay approximately half the time in Tokyo and Osaka (8-9 days) and want to sightsee the rest of Japan. I want to know the most economical cost for travelling within and between the two cities and across Japan. Questions:
Can I use JRPass in Tokyo and Osaka?

If so, my options are:
A. If I can use the JRPass in Tokyo & Osaka, then I should purchase the 14 day JRPass
B. If I can NOT use the JRPass in the 2 cities, I guess I should purchase the 7 day JRPass, plus the local subway/metro within each city

Last question: Is there a stop at the Narito (NAT) airport that takes you into Tokyo? Thank you!