KneesUp
Guru
Can you dog distinguish between a burgular and a child retreiving a ball, or a passer-by trying to inform you that there is smoke coming from your window etc?Another of your questions is a little odd and the check box saying home/garden need separating. If one of my dogs bites an intruder to my home, that's fine and dandy. If they bite an intruder to my garden, I can be prosecuted.
Personally, I think that if I have an intruder, they deserve all they get but Greyhounds are likely to wake up, demand a treat and go back to sleep.