Hi Werner,
Sorry for the delay. Have you made any progress?
1) The pooled invoker isn't part of Remoting, and I'm not very familiar with it. I don't believe it is used by default in any Application Server subsystem.
2) There is no way in Java to control the ports assigned by ServerSockets. However, the range can be set at the operating system level. For example, see http://http://www.ncftp.com/ncftpd/doc/misc/ephemeral_ports.html
-Ron