Should I buy the JR Pass?

Hi,

I will be landing at Narita Airport on 3 Nov and on the same day travel to Osaka.

In Osaka (3 Nov), i will be staying for 1 night and on 4 Nov evening, travel out to Kyoto.

In Kyoto (4 Nov), i will be staying for 3 nights and on 7 Nov travel back to Tokyo.

In Tokyo (7 Nov), i will stay for another 5 nights and on 12 Nov morning return to Narita Airport.

Please kindly advise if it is worth purchasing the JR pass?

Also, does the JR pass include the fee for reserved seating? Or do i have to pay additional money for reserved seating?

Thank you.