Step 9: do not symlink over /bin/sh.  This will slow down your system, and will be broken by any updates that reinstall dash.  If ISPConfig requires bash, fix ISPConfig -- don't break the OS.

Step 10: do not uninstall AppArmor.  If there are specific services that are modified to work outside of the existing service profiles, just disable the one profile until you can fix the profile.  For example:

  aa-complain bind9

Then review your logs (via dmesg or /var/log/messages), and update your profiles:

  aa-logprof

For more details on how to use AppArmor and other new features of Ubuntu, please read the official documentation:

 https://help.ubuntu.com/community/AppArmor