10 day itinerary - Kansai region

I am planning a 10-day trip over Christmas and New Years to the Kansai Prefecture. This is my second time visiting the area, and I�fm looking for feedback on my itinerary. During my previous trip, I went to Kyoto, Osaka and Nara. I loved Kyoto and definitely want to go back a second time.

A few questions:
- Am I cutting it too close on timing for Awaji sightseeing (2 afternoons, 1 morning), Himeji Castle (1 day), Arima (1 morning) and Mt. Koya (1 morning, 1 afternoon)?
- Should I consider other places or prioritize differently?
- I�fm also wondering if I should stay at ryokans in Awaji and Arima rather than going back and forth to Kobe as a home base for the first two nights. I want to enjoy the time at the ryokans and don�ft want to feel rushed on sight seeing as I remember having to check-in to ryokans before 5PM, which is why I�fve planned it this way for now.
- Any suggestions for rental car vs. trains? I've elected to go with the rental car because I think it will significantly cut down travel time to far-off locations. I'm also wondering if I can rent from Kobe and return to Kyoto. I've rented a car in Japan once before when I visited Shodoshima island, but I picked up and returned at the same place.
- Any general advice on travelling over the Christmas holiday? From what I can tell most places are unaffected until the New Year celebrations, for which I plan to be in Kyoto.

Here is my itinerary so far:
12/23: KIX - Kobe - (arrive 430pm), go to Kobe, stay 2 nights in western hotel
12/24: Kobe - Himeji - rent car (45 min drive), sightsee Himeji, return to Kobe for dinner
12/25: Kobe - Awaji - leave Kobe early am, sightsee Awaji, stay 1 night ryokan
12/26: Awaji - Arima - sightsee Awaji, drive to Arima, stay 1 night ryokan
12/27: Arima - Mt. Koya - morning in Arima ryokan, leave by 1PM for Mt. Koya (2.5 hr drive)
12/28: Mt. Koya - Kyoto - leave Mt Koya late afternoon, drive to Kyoto (2.5 hr drive), return rental car
12/29, 12/30, 12/31: Kyoto
1/1: Kyoto - KIX (depart 6:10pm)

Would appreciate any feedback and suggestions!

I visited Awaji Island once, and it's not exactly a major tourist destination. There are onsen ryokans there, but so do hundreds of other destinations. There is an anime theme park, which I did not visit. Unless you have a specific reason to visit Awaji Island, I would not spend so much time there, or select another destination all together. No trains to Awaji, so buses from Kobe is pretty much the only way to get there.

All the destinations you are traveling to except Awaji Island have good public transport options.

To save money on car rental fees etc, I'd just stay extra time at Kobe and rent a car for one day to visit Awaji Island.