Hi Mr Fader
I get this message too. (about the ARDAgent) I don't think it has anything to do with Logic.
If you google it there are a huge number of comments about it, going back from years, but this link is from Apple:
its titled "Disk Utility's Repair Disk Permissions messages that you can safely ignore"
and here's some more info: "ARDAgent is a faceless (no dock icon, no windows) helper application for Apple Remote Desktop. Used in a lab setting, ARDAgent is very useful for people who use Apple Remote Desktop to manage a large number of Macs; it can run programs on behalf of the remote administrator, for instance."
So thats OK then.
Unfortunately I know nothing about vectors (yet), but I'm sure the combined genius of Steve and Rounik will see you through