How to implement a data warehousing solution for Google Analytics data?

I have click stream data such as referring url, top landing pages, top exit pages and metrics such as pageviews, number of visits,
bounces all in Google Analytics. There is no database yet where all this information might be stored. I am required to build a data
warehouse from scratch(which I believe is known as webhouse) from this data. So I need to extract data from Google Analytics and
load it into a warehouse on a daily automated basis. My questions are:-

1)Is it possible? Every day data increases (some in terms of metrics or measures such as visits and some in terms of new referring
sites), how would the process of loading the warehouse go about?

2)What ETL tool would help me to achieve this? Pentaho I believe has a way to pull out data from Google Analytics, has anyone used
it? How does that process go?

3)How does Google Analytics interface with Pentaho and in what ways can you use the features from Analytics right inside Pentaho?

Any references, links would be appreciated besides answers.

As far as question #1 goes, sure, of course it is possible. I am not familiar with what Google provides, but from what you describe, it sounds like aggregate data. I've developed clickstream warehouses that maintained individual page views without significant challenges that had fact tables in the many billions of rows with good performance.

As far as ETL tools go, there are a lot of products out there, most of them good. Choose one that you can afford and provides the functionality you need.

As far as interfacing goes, how does Google provide the data? If it is just a download, where they provide a flat file or XML file, most ETL tools should be able to handle it.