labs are great dogs as pets we have one who is simply a pet and was never trained. nonetheless he loves the water and his people and meets most of the criteria you have set out except for the guard dog part. he wasnt trained, as i said but still has the instinct. he loves to chase any kind of birds and will go fetch things but not bring them back to you. he's even caught some younger ducks that cant fly really well and holds them gently enough that a couple have gotten away again on him.