Hi David,
Regarding the use of log4j appenders, I asked this question a couple months ago in the forum and the general response I received was that I would have to create a custom appender.
https://community.jboss.org/thread/176103
The custom appenders required you to implement a JUL interface, which had no support for MDC. Maybe this has changed since then?
Are there any up to date articles or discussions that demonstrate how to use a a log4j appender in conjunction with the jboss logging?
Thanks,
Dan