I have the same issue as everyone else with the contacts and I have never used Google+, never even signed into it. I am also getting google play services with the same error message. I have a S5, Android 5.0. I did a factory reset after the update as well as the cache wipe that I have seen people talk about... still getting error messages.
I am also having the alarm issue, I thought I was sleeping through them as well, but apparntly not. I do see in the morning that I have "missed" an alarm, but it never went off. I have the phone turned up, volume on etc.. Not a happy camper with 5.0 :-(