Has anyone successfully created a mapping to a database view in SQL Server?

Yes, I have. The trick here is that if you *really* want updatable views with complex join scenarios, you need to look into also using a feature called INSTEAD OF triggers. This is a SQL Server feature only that allows you to define the UPDATE, DELETE and INSERT behavior for a view.

another point is, that you have to define a primary key column even if views don't have a primary key. You can take any column of the view which contains unique values. For views which don't have columns with unique values we define a dummy column like "newid() as ID".