Is there a way to exclude fields from being used in the BO?

You can bind a view to the business object, but only for displaying data from the business object, not saving back to the database.  The primary key is defined on the table, not the view, so when the BOMapper creates the partial class for the business object built from a view, it doesn't include the primary key.  You'll probably have to wait until I get the exclusions done for the updates.