Which way i should take (Chugoku region)

I'm planning to visit some or Chugoku region via Osaka (Kansai airport) on this autumn; Tottori (Conan Museum & Sand dunes), Hiroshima (Atom dome, etc & Miyajima) and Okayama (City & Kurashiki).

1. Is it correct to choose 14-23 November to enjoy autumn foliage in those places?

2. Am i had enogh time for those itinerary?

3. Which route i should take?
Kansai airport-Tottori-Okayama-Hiroshima-Kansai airport,
Or
Kansai airport-Okayama-Hiroshima-Tottori-Kansai airport?

4. Which pass i should take, JR Pass Sanyo San'in or other?

Thanks for the responding^^

Either travel option will work for you. They are the same route, just reversed.

A 7 day pass probably wont work for you as you have 9 day total. So you need to calulate whether the 19000 yen pass pays for itself eg KIX Okayama Tottori Hiroshima or not. You can use hyperida or similar website to calculate trips.

Those days look about right for autumn colour going by last years reports. I am planning something similar (finances permitting) but going to Matsue not Tottori. My plan is to be in Japan Nov 16th to 30th. Whether it is long enough is up to you particularly how long you intend to spend in Tottori.
Given the way the rail lines work you are likely to pass near Okayama or Kurashiki on the way to & from Tottori so I would break the journey that way. I would probably do Hiroshima, Okayama, Tottori.
I would buy the Sanyo-San'in pass as it will be cheaper than the individual fares.

KIX to Tottori 8590 yen
Tottori to Okayama 5210
Okayama to Hiroshima 6430
Hiroshima to KIX 12350

These are your four long distance trips. One of you to/from KIX days wont fit into the 7 days of pass. So I'd pay 8590 yen to get to Tottori, and have your pass active for your final seven days. But that only works "IF" you have 2 nights in Tottori.