No, Role Scoper does not provide any additional XML-RPC interface beyond those defined by WordPress in xmlrpc.php. The content exposed by those WP interfaces is filtered as in wp-admin, but there is no way to set RS roles and restrictions via XML-RPC.

If you would like me to estimate the cost to develop that additional API, please submit a Service Exploration Form. I've traced through xmlrpc.php enough to have a good idea how to do it, though I would require someone else to develop the XML-RPC client for testing and implementation.