The female will most likely die from birthing as the puppies will be to big for her to birth naturally, she will then get complications and be dead by the time your emergency vet has arrived to perform a C-section.
doing his buisness
27 inches
It could be that he is just hot, all dogs sweat through their tongue, which causes them to pant. My male Rottweiler is exactly the same, so I don't think there is anything really to worry about. They are just big bulky dogs.
Nearly 12.
there big
Not that big and a little chubby
I think you mean either a Doberman or a Rottweiler.
58-69 cm is the average height at the wither.
Large males weigh 120 to 150 pounds.
It isn't aggression. It's a six month old acting like a normal six month old. A six month old puppy is too big to play with three month old puppies. He's going to mow down the other puppies and it doesn't mean there is a thing wrong with him. He's just bigger, stronger, more coordinated, and more confident than puppies half his age. Choose play mates for him that are of a similar age, similar size, and similar activity level.
A LOT! If your dog has puppies then it could take up to a whole house for them to play and run around. You can keep it to a limit though, like maybe a large living room. If you have dogs and puppies though, it might be better if you keep the big dogs (except the mother and father) away from the puppies so the puppies do not get hurt. Especially if you have newborns and older puppies like 9 month olds, because the older puppies don't know what's right and wrong and could play to rough with the younger puppies.