Using what MS calls schemas to separate different parts of the data is fine, but I don't think a hierarhic relation between schemas would make sense: SQLServer is a (nearly) relational database, not a hierarchic datastore.

Also, it is important to remember that all the data in a database has to use the same recovery model, even data in different schemas, which is just one of several reasons why the ability to put things into different schemas doesn't always allow you to put things into the same database without unpleasant consequences.