JR Rail pass - Ticket Availability during December last week

I'm a first time traveler to Japan. Had a couple of basic questions.

1. I'm planning to travel to Japan during the last week of December, from Dec 23- Jan 1. I know it will be a holiday period and trains will be crowded. Will I be able to get tickets using JR Rail pass to travel between
   a) Tokyo to Osaka on Dec 24
   b) Osaka to Kyoto on Dec 26 c) Kyoto to Hiroshima on Dec 28
   d) Kyoto to Tokyo on Dec 29 ?

I believe with JR Rail Pass I cannot reserve the tickets beforehand and I can only reserve once I reach Tokyo on Dec 24th

1. For the temporary visa, I will need to submit 'Confirmed travel booking with day to day details'. If I'm planning to get a JR Rail pass and since one can only do the actual booking upon arrival in Japan, how do I submit the copies of the actual ticket as part of the Visa application supporting documents? Will just the JR Rail pass do as evidence of travel bookings?