I can help you with the first and the third question, I don't know about the second.
First, why are ANYONE callbacks listed under the view for a single user?
I suspect it's because even though a callback can be set to 'ANYONE' the user field is still filled in in the database (have a look at the vicidial_callbacks table).
Why aren't these callbacks being dialled, the have a callback date in the past.
As far as I'm aware ViciDIAL processes ANYONE callbacks in 15minute chunks. If your agents fail to go through all the ANYONE callbacks in a particular 15min time period ViciDIAL will leave them alone and expect manual intervention. This makes sense really, it's not a call back any more if you don't call back when you said you would.
ViciDIAL will always expect agents to dial USER ONLY callbacks manually themselves. When doing automated outbound dialling it's not possible to guarantee a particular agent will be available at the set callback time to take the call.
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