best way to enjoy the best of JR Pass

Hello! Could someone please help me check my itinerary? I'm evaluating whether it's worth buying the JR Pass. I will spend 15 days in Japan next month.

First part of the trip:
Tokyo – Takayama – Shirawana Go – Takayama

Second part of the trip:
Takayama – Kyoto – Hiroshima – Osaka – Tokyo or Takayama – Osaka – Hiroshima – Kyoto – Tokyo

Questions:

Are these routes covered by JR Pass?
Should I do Takayama – Kyoto or Takayama - Osaka?

Thanks very much!