I just love dogs, I wonder if there is a carnivorous animal more abundant on Earth ?
I agree dogs are cool and loyal. I can't think of a more populace carnivore besides us at the moment.
Are they related to wolves ? they look alike, but they behave quite differently. 
That's interesting, I think they are a different species than wolves but perhaps they have a common ancestor
Do you think they were the first domesticated animals ? I would think it would be something more useful, like a cow or a chicken. 
Based on popularity they come to mind in that list, but I agree with you that other animals had more functional benefits and were first.
But I can't think of another animal that can fulfill so many roles: hunting, herding, protection....