Power BI Architecture with Azure Analysis Service Different connection modes

Hello,

We have around 50 power bi reports connected Live to On-Premise Analysis Services, and we are migrating to Azure Analysis Services.

When it was on premise it didn't matter if it was Live or import because we are were not charged by hour or throughput or data movement

But after migration I am confused which connection method I should select in order to achieve highest performance with least costs.

As far as I know, I can connect azure analysis service to DB by 2 methods: (Import or Live Connection)

and I can connect power bi to azure analysis service by 2 methods: (Import or Live connection)

Important Note that data is refreshed daily ( Not Real time data)

So I have some questions:

1. Analysis Services pricing is by hour, so If I am refreshing the model daily from DB, and let's say it takes 1 hour to process all the cubes, will I be charged 1 hour or 1 hour + all querying time that come from dashboard viewers when they access dashboard is live connection mode?

2. Is there an option to connect Azure Analysis service to the DB by import, and storing the data in the cube itself, and connecting power bi dashboards to this cube in live connection mode? ,, and how is the pricing calculated in this method?

3. Also since all the current dashboard that we have is live connection, is there any automatic way to make them import mode to the cube? I searched but couldn't find.

4. What is the best architecture for the semantic layer between Azure analysis service and power bi, knowing that power bi Premium capactiy is not an option in my company?

Thanks