Yes. The DefaultView of the data table is what makes the "fitler" happen. As for the contents and the filled data, yes as well.
No. It means that if you call the navigate on one BO it will not affect any other BO using the same shared data table. This is when you will want to use a ChildFormDialog or a BOTranslation as the handlers and everything are translated between two or more sessions.
Any BO which has the same SharedDataTableKey will have the same data within the BO.