Like I said, phoebe gets hit regularly at her house but she is super excited when her owners walk in the door, she runs to greet them. She loves them. They feed her, sleep with her, play with her and walk her, they are her family, so I don't think she would leave them.
It will do nothing to stop dumpster diving, counter surfing and chicken killing.
Supervision is key during training, but commands can be taught as can behaviors so that supervision is no longer needed. It's just easier to put the trash in a cabinet. These things can be taught with positive training. A dog can be taught that waiting earns him food but breaking the wait gets him blocked from the food and therefore does not work. Yes it's supervision but once the dog is taught it does not work he will stop. yes you could smack the dog, collar pop the dog or scream at the dog (although a great number of dogs will not care about your yelling when there is food) but there ARE positive ways of doing it, they may take longer but they last and you don't have to scare the dog. The dog learns for himself that he cannot get the food no matter how hard he tries so he chooses to stop. you can also teach a command incompatible with the behavior but those are usually for while you are in the room or are stepping out for a few moments.
I'm not saying I don't punish, I do. I use removal (of myself, attention, the dog, food, toys/games etc.) but that's pretty much it I think.
I'm not saying punishment will destroy your dog, though it may some, and I'm not telling you you are "doing it wrong" or to stop, I'm just saying there are other ways that work and for ME punishment is not the way to go because I don't have to and don't really want to.