Kansai Hokuriku Area pass

Hi, we are 2 adult who going to Japan on 2/4/25 and returning on 13/4/25. We choose Osaka as base and want to use Kansai Hokuriku Area Pass to travel to some cities.
1. From day 5/4.25 we want to activate the Pass about 9 AM to travel to Himeji castle and Kobe.
6/4.25 to Hiroshima and Miyajima ( overnight 1 night )
7/4.25 back to Osaka
8/4.25 Kanazawa (overnight 2 nights)
10/4.25 back to Osaka about 10 AM from Kanazawa station.
Question: is this pass covered this itinerary ?
2. Should we buy the Pass 1 month in advance?
3. Will we activate the pass on 5/4.25 in Namba station to begin the route to Himeji and Kobe? (our hotel in Namba Area)
4. Is it better to get non reserve seat in case we miss the train and we can get the next one?
We hope the Japan JR pass expert can help us with this itinerary.
Thanks alot in advance.
Hng