As far as time sync issues? Ouch. My time wasn't in sync before the installation of ZCM so all my certs were bad (date was out of whack too for some stupid reason). That's what I get for using prebuilt lab images that weren't on the domain first.
What about changing the IP address? That one nailed me hard a few times as I tend to forget to static the IP before installing ZCM. Changing it after the fact resulted in services not starting anymore. Yay! One more reinstall for the road!
Oh, and System Update on my primary server caused all my secondary servers running PXE services at remote sites to also go to 100% cpu utilization.
ZCM is a little more bleeding edge than leading edge in my environment. But it does have awesome potential.