If you don't plan to visit Hiroshima, you don't need a JR pass based on your original itinerary.
www.japan-guide.com/railpass = rail pass calculator.
Welcome to the TA forums.
FYI - Kyoto and Osaka are less than an hour from each other via train. You might want to consider staying in one city and do day trip...
Use luggage forwarding service- https://www.japan-guide.com/e/e2278.html
It makes train travel so much easier.
Please learn how to use www.hyperdia.com for train routing options throughout Japan. Google Maps works too.
Plug your proposed destination into Google Maps. You can see what’s nearby along with transit options to wherever you plan to visit while you’re here.
It couldn’t hurt to call. Your credit card company might be blocking it if they suspect that it might be fraudulent.
Did you contact your credit card company to let them know that you’re using your card for a purchase from Japan?
The pass is based on consecutive calendar days,