JRPass - Tokyo, Osaka, Kyoto

Hello,

we will be travelling to Japan from 11th until 23rd of August and I would like to know if its worth buying a JRPass for our travels.

We are planning on visiting the following places in Japan:
Tokyo, Kyoto, Osaka, Nara, Himeji, Kobe and Nikko.

Is it worth getting the JRPass for two weeks to travel to all these places?
Can we use the Pass to ride subways in Tokyo, Kyoto and Osaka?
As we are arriving in Tokyo we would like to use to ticket to get into the city - is that possible?

Thank you very much in advance!

Best Regards
Susann