Kansai-Hiroshima Pass

Hello JRPass, Thanks for this forum. I’m just wanting a bit of advice please,
- we’re travelling through Japan for 2 weeks and see the JR Kansai - Hiroshima Area Pass might be the best value to cover the following part of our itinerary, would this be correct? Day 1: Kyoto – Nara & Uji day trip
Day 2: Kyoto – Osaka
Day 3: Osaka – Universal Studios
Day 4: Osaka – Hiroshima/Miyajima
Day 5: Osaka – Himeji Castle
- Are we able to buy the pass before arriving in Japan then activate it in Kyoto on Day 1 of this itinerary? - If we take JR trains in the Osaka area, are they covered with this pass as well? Thank you for your help.