Can I hide the WordPress toolbar from subscribers?
Yes, you can!
As of version 2.7 there's an option in the settings panel for this very purpose. Navigate to Restrict > Settings > Misc and find this setting:
When checked on, the toolbar will be disabled for all users except administrators.
If you also want to ensure your members can't access any parts of the WordPress dashboard, you can install the Remove Dashboard Access plugin from WordPress.org.