Data in Staging area

I have created a small star schema datamart for developing my SSAS Cube skills and have a few questions.

1. Once data reaches the staging area is there any relationships that need to be built? Please read below and
let me know if I am accurate. Thx.
Current thought:
Here is my thinking at this point. The data in the staging area is raw. No relationships No joins.
The Relationships are first built in the Star Schema in the datamart with PK & FK only. Further
relationship building is done in SSAS with dimension usage & attribute relationships, etc....

Please leave comments.

I am not sure if I fully understood your points. But you don’t let users or cube to use the staging area directly which is only used by ETL process. The data in star schema should have strong referential relationship between fact and dimension tables, as the prefered user/cube facing schema for your reporting and cubing requirements.

However the attribute relationship in the cube is about creating hierarchies for aggregate navigation. Dimension usage controls whether the dimension attributes and its related hierarchies should apply to the relevant cube aggregations.