Oke, it was a stupid question :-)
At least the second part. The "test"-classes are examples, not required classes according to the documentation.
RTFM for the second part of my question thus :-))
But my first question remains, what's the best part to put the JAR libraries and which are required to get Remoting up and running?
First step would be to be to replace the jboss-remoting.jar as you mentioned. Only possible impact this might have is if are using ejb3, which uses remoting (otherwise, will have no other impact on JBossAS and even then, should be compatible with the newest remoting version).
Next is which config you are using for remoting (transport, serialization, etc.). If using the socket or rmi transport, should not need any other jars. If using http, will need to copy tomcat-apr.jar, tomcat-coyote.jar, tomcat-http.jar, and tomcat-util.jar to the lib directory. If using jboss-serialization, will also need to add jboss-serialization.jar to lib directory.
We have a jira issue to document all this (http://jira.jboss.com/jira/browse/JBREM-311), so should have it published soon. Also note, that since the classes are loaded on deman, won't know what classes you might be missing until actually make your call (which stinks, but is better than having to include all the transport jars when just using socket transport).
Thanks for your reply :-)