I think Ann has given you great advice. I also think you should visit with a rescue or shelter to make sure you get a dog that will be a good match for you. You can also stop at Vet Clinics. They know all of the dogs and the families that they see. They may know about a dog that would be perfect for you.
To answer your questions:
Breeders seldom train their dogs. Since most of them only have the dogs for breeding, they dont care about them beyond that. When they reach a non breeding age they are usually given to someone else (like yourself) to give the training. But it is often a big job and most of these kinds of dogs end up in shelters or are put down.
Yes, they "Should" get some training and socialization. The basic stuff would be a huge plus, but until the laws are changed, or until breaders grow a concence I dont see it happening.
DONT GET ME WRONG, there are a lot of great breeders out there. Ann got Baloo from one, and I fould a great one when I got Chip years ago. You just need to do a lot of research before you buy.
There is no better way than to ask them to be honest. If they say that they work with the dogs, ask them to show you. If the dog doesn't listen, do any basic obediance, or is not used to a leash ... it has probably not been worked with.