Is iTunes Streaming Server really off?

Did you remember to click Apply after unchecking it?

Yes. And the NAS has been restarted many times with this behavior.

After an OS re-install I see this in the log.

Nov 17 10:52:59 ReadyNas avahi-daemon[3450]: Service "ReadyNas iTunes Server on ReadyNas" (/etc/avahi/services/mt-daapd.service) successfully established.

In Frontview the iTunes Streaming Server is unchecked (v 1.0.3).

How can I remove this from the services starting up?

Are you comfortable with SSH?

Reasonably. I don't play around in terminal too much anymore but know enough to to randomly change things without understanding what I'm doing. I wasn't sure if just removing the .service file would fix the issue or if there was a .conf file I needed to tweak.

Removing that file should work (would need to restart avahi for the change to take effect).

Also what do you see if you do this?:

# cat /etc/default/services | grep DAAPD

DAAPD=0
DAAPD_SUPPORT=1

So it is turned off. Removing the .service file then restarting avahi (either restarting Bonjour in Frontview or manually via SSH) should be sufficient.

It won't mess anything up to have references in the services file?

No, leaving those is fine. DAAPD=0 indicates that it is disabled. If you remove those lines you would have to add them back or do an OS Re-install to be able to use the iTunes Streaming Server again,