Are these your first guineas? They are very independent/wild birds. They can be tamed to a certain degree if you put a lot of hard work from when the were keets. They are very weird animals but very enteraining and once you get used to their noise its just a normal sound. They will wonder aimlessly around for a bit until they know that is their new home, may take a few weeks to get used to you and your surroundings. After that you can let them free range if you want to and they should return to the coop, but be aware if you have any nice trees by the coop they may start roosting in those.
I have never had a problem with guineas and other poultry. They tend to keep to them selves and if anything the turkeys and chickens bully the guineas. Yeah forgot about the tree roosting! I just gave up clipping wings and just let everything fly where ever it likes, but I do have a seperate enclosed yard for my red eyed guineas whom have bad eyesight and would be killed by predators within seconds if let out. I have around 100 guineas and dont often see snakes and thats probably because there us so many, so I dont know how your 2 guineas will go with rattlesnakes and other unwanted pests.