You can add and remove the karma value by yourself (in the officer management) and you can add it automatically by the activity (this can't be deactivated).
Means it mainly shows you the activity of your officer, but you can still influence it yourself.
You have to assign the security level to each officer yourself.
For files, appointments and so on you can also assign security levels.
For example, if a file has security level three, only officers with security level three can see it.