I know this is a Very late reply but maybe it will help someone else with the same questions.
I am no expert on this but I have been raising free range chickens, ducks, geese, turkeys, and goats on 38 acres with the help of 2 eleven month old brother and sister Anatolian Shepherds (Jack and Jill). They started protecting my animals from the time they were four months old. There is no way I could free range my animals without them. I have never lost an animal to a predator.
I did not raise my LGDs to bond with a herd of goats or sheep the way most ranchers would. My LGDs are farm dogs and part of my family. They protect me, my animals, and my property.
I picked Anatolian Shepherds over the Great Pyrenees because I wanted an LGD that did not get burrs and mud stuck to their coat. I also do not have to shear them in the spring so they do not die of heat stroke in the summer like a GP.
1 - I would HIGHLY recomend getting 2 dogs. Think of them as 24/7 security gaurds. When one is sleeping the other is on gaurd. It is also great for them to have back up and a playmate. All of my birds and goats are in a 492' electrified poultry net fence at night. The dogs house is facing the fence but is on the outside. They patrol the perimeter from time to time at night. The ducks and geese have pretty good night vision and will sound the alarm if something is not right. The dogs react to the noise. In the morning I open the gate to the pen and the birds and goats come and go as they please. The dogs seem to take turns napping near where the goats are hanging out outside the pen. The only animals that travel some distance (more than 300 yards) from the pen are the turkeys. The dogs have given up on keeping an eye on them. I have seen coyote tracks and scat at the back end of the pasture but never closer. Jack and Jill regularly mark that boundary. I have never seen raccoon or possum tracks past that boundary either.
2- If you are raising your goats and sheep in fenced pastures far from your house you will most likely want the puppy to bond with them only. In that case you will want to start with one puppy otherwise two puppies will bond with each other and not the sheep.
I raised my dogs to protect my property and everything on it so I have no experience with this method.
3- I looked at the rescue for Anatolian Shepherds but was put off by all their rules and by the posibility of an adult dog not bonding with me and my animals. Rescue would be fine if I was looking only for a pet. That is just my opinion.
4- I have no fences on my 38 acres (I am surrounded by woods and my nearest neighbor is more than 1/2 mile away) and my dogs patrol at least the half that is pasture closest to the house, barn, and pen. Ever since they were puppies I would walk the property lines with them. I let my 3 neighbors know that I was trying to train my dogs to stay on my property. Each of my neighbors fired a shot in the air if they seen my dogs on their property. My dogs never returned to my neighbors properties after that. NEVER take your dogs with you when you visit a neighbor. They will think that the neighbors property is theirs afterwards. My neighbors friend's pitbull made the mistake of coming on my property near the pen. Jack and Jill chased it like they wanted to eat it and it was screaming all the way. Luckily it made it home alive. One of my neighbors has 2 Great Pyrenees and they regularly leave calling cards at the gate that separates our properties. Dogs do not respect fences but they respect other dogs calling cards. :)
You do have to introduce new animals to them in a controlled manner. Every new bird I bring to the property is caged and then I let Jack and Jill smell it. Once they have smelled it for a few minutes they will walk away as if they have lost interest in it. You do not have to do this with chicks and ducklings that hatched or were raised in the pen. I guess they have the right smell. If it is a goat, I tether it and let them smell it. Once they have smelled it they seem to know that it is not a threat and is accepted as part of the property to be protected. When one of my goat does delivered twins Jack and Jill wanted to smell the new additions but the momma goat was not going to have it. She knocked Jill completely on her back for getting to close to the kids. Jack and Jill had to make due with smelling the ground where the kids had walked.
My dogs have nevered acted aggressive towards my family and friends that they have been introduced to. However, they do bark LOUDLY at any vehicle they do not recognize and are very intimidating to strangers until I introduce them. Make sure you are there to introduce them to the UPS guy, meter reader, etc. anyone who has your permission to be on your property. After the first introduction they remember the vehcle and the person.
Like with any dog you should correct any signs of aggression starting when they are puppies. These are BIG dogs (at 11 months Jack is 132 pounds and 30" at the shoulders. Jill is 107 pounds and 28" at the shoulders) and if they do not see you as the Alpha they will take over the position for you. I have always been firm but fair. Jack started showing aggression towards Jill at 5 months but that stopped once I had them both fixed. They are not going to win any dog obiedience contests but they should at least know the commands NO, stay, and come. Jack and Jill picked up no and stay pretty easy. They will come as long as it does not involve them having to get up from a sleeping position (they are nocturnal and take a lot of naps during the day). Jill learned to shack hands from my sister in law and now she wants to shake hands especially when she has mud on her paw. :(
If you want to protect your animals and property you cannot go wrong with a well trained LGD or two. Good luck.
Jack and Jill resting with the geese. In the background is the electric fence pen. All the animals (except the dogs) go into it on their own at sunset. Dogs are never allowed in the pen. They think it is a big Easter egg hunt.
Jack with a goofy look on his face with my Cocker Spaniels Molly and Maggie
Jill with her smiley face. She was the only pure white puppy in the litter. All of her brothers and sisters looked like Jack.