Wanting to hear some opinions before I get much farther into this.
I'm creating 3 web applications with distinctly separate parts but related sets of data. Think of it as a master application and 2 child applications. The master app needs to see all sets of data, but the children are limited to their schema - master.whatever.net = entire db, app1.whatever.net = app1 schema, and app2.whatever.net = app2 schema.
We use Windows Authentication to SQL Server, and permissions on each schema are granted based on specific security group memberships (master_group, app1_group, app2_group). The web apps themselves use AD Authentication for both username/password and group membership when signing in. The application server restricts db access to the schema required for the app.
Common tables used between apps are kept in dbo, while app-specific...