Matt,
We have used a similar document that contains some of the same steps so I figured I would look at the differences and try to perform the differences in the file you posted that where not done.
This is where I ran into problems.... the JCE Policy files... I have no idea which ones I should be using, i viewed the note and still can't determine, were on oracle11g with red hat linux as the server OS.
According to my workmates this machine shares a sapjvm install with NWDS but when I login as idmadm and do a java -version I get JDK...
java version "1.7.0_09-icedtea"
OpenJDK Runtime Environment (rhel-2.3.8.0.el6_4-x86_64)
OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)
Could this perhaps be part of the issue....that it is not SAPJVM?
Also at the bottom of page 5 per the document you mentioned the script that it says should be in the home directory is non-existent. postinst.sh does not exist anywhere on the system.... I don't even see it if I look into the CD image of the IDM install we used...