Well, they've done studies, and I think your dog will kill you if you don't find him a new home. Dogs that annoy their owners in the way you described will almost always try to kill their owners when they become adults. And Newfies are pretty big dogs, so... it's best to rehome, because you could not fight a dog like that off. However, they found if the owners rehomed the puppies that exhibited this annoyance behavior, with people they weren't related to, the puppies invariably led happy normal lives.
To put it in terms that are easier to understand: your puppy is showing signs he will turn evil IF he stays with the same person he's been with (you.) If he's with someone else, he'll be fine, but with you, the syndrome will progress until he turns on you. They call this strange phenomena (meaning:weird thing that happens) Canine Benighted Owner Syndrome.
So take your dog to a shelter ASAP, so your dog doesn't attack you. You can explain he likely has Canine Benighted Owner Syndrome (C-BOS), but either way, get him to someone new before he kills you.