If you define all of your pages, portlets, portlet instances, security constraints, roles, etc in the xml file descriptors instead of using the management portlet then yes, you can basically copy your configuration folder over and it should work. If you do anything in the management portlet to set up your portal, those changes will not be carried over. The only way to copy changes not specified in the descriptors would be to export the tables from your test database.
zerrt is right, descriptor files are the way to go when defining a portal. The only thing I haven't been able to define in a descriptor file is login accounts and roles (someone prove me wrong, please).