I guess that what you apparently want to use schemas for is what MS intended to provide by providing complete separation between the schema concept and the user concept. So yes, it's reasonable to use them that way.

However, there can be issues which may persuade to keep some schemas in separate databases. Putting data for which the full recovery model, frequent incremental backups and fairly frequent full backups is appropriate and data for which the simple recovery model and infrequent backups is appropriate into schmata in the same database is going to use extra storage (for unneccessary backups, unwanted data in log files), slow down recovery on service startup for data for which simple recovery is appropriate, probably introduce complications in administration as a result of attempts to alleviate the increase in storage requirements, and certainly increase teh performance load of backups and of logging. So, as usual, what's best for you depends on your data and what you are doing with it.