I see there is a document for preparing a windows client to be baked into an image here, but I haven’t run across one for Linux/Unix. I’m going to assume the core steps are the same.
That would be the basics yes. If any other content wrote directories to the /var/opt/BESClient directory then you can remove those too.
One of the easy ways is to never start the agent up at all. When you install on Linux/Unix you have to manually start the agent so if you skip that step (making sure the masthead is in the right place etc) you have nothing to even remove.