Some questions about Weimaraners?

They were bred for retrieving waterfowl- not actually hunting it. What is important about gun dogs is that they are very energetic. A weim will need plenty of structured exercise (as an adult, two hour long leash walks per day plus a couple times a week of frisbee, swimming, etc) They are fine with children and visitors if all are properly trained. I highly recommend crate training or doggy daycare until the pup is out of the destructive stage (usually the first 2 years, but some gun dogs are slow to outgrow that especially if not properly exercised). Fine with smaller dogs and cats if properly socialized. The size of the yard is pretty irrelevant as it is really only used to as a convenience for the owner. A romp in the yard should never be mistaken for exercise.