Shin-Osaka to Iwami - Clarification required

Hi

I'm making my way from Shin-Osaka to Iwami in Tottori.
The recommended route by Hyperdia (as I wanna reach as early as possible for my day trip) is as follows:

SHIN OSAKA to AIOI (Hyogo) via Shinkansen
AIOI (Hyogo) to KAMIGORI via JR Sanyo Line
KAMIORI to TOTTORI via Ltd Exp Super Inaba 1
TOTTORI to Iwami via JR San-in Line

I will be using my JR Pass for this.
1. Am I correct to say the Shinkansen and JR Sanyo & JR San-in Line is covered by JR Pass?
2. I know a top-up is required. Where and when do I pay this top up? Is it from KAMIORI to TOTTORI that I have to pay this top up/buy a new ticket?

Many, many thanks in advance.

Suanz

The non-JR section is between Kamigori and Chizu (Chizu is south of Tottori):
http://www.japan-guide.com/e/e2368.html

I believe that you can either purchase a ticket for the Kamigori-Chizu section in advance at a ticket counter or pay the supplement on board of the train.