Do not set JBOSS_HOME, nor add jboss_home/bin to PATH. If you examine run.bat, you will notice that the first thing it does is set JBOSS_HOME based on the location of run.bat.
On my system I have countless installations of JBoss AS, with various different versions. I do not have JBOSS_HOME set, nor have the bin directory in the PATH. And everything works just fine.
The only thing you really need to set is JAVA_HOME.
Thanks! I put the export in run.sh, but same concept. :)