I'm not saying you misread Zero, please don't think that. But, usually the noisier a dog is, the less you have to worry about. And, by that I mean, dogs bark. They bark when they're scared, when they're excited, etc...not necessarily when they're being aggressive. An aggressive dog usually doesn't make much noise...maybe growling, but, that's why you hear so many stories about dogs attacking and the person will say that they didn't even bark. And, I'm not a behaviorist by any means. And, I'm also not saying that you did the wrong thing by restraining Zero. Because, when there are children around, it's better to be safe than sorry. But, I will say this...I would invest in a crate for Zero if he doesn't already have one. He needs to have safe spot for him to go into when he is acting that way. He may feel threatened. I don't know. And, I would get him into extensive training. And, I'd maybe even get in touch with a behaviorist to find out what kind of message Zero is trying to convey with his excessive barking. It may not be what you think at all. And, as for him being loud and disruptive, he just, again, needs some training on manners. He's much too big of a dog to allow him to get away with behavior like that. Good luck with everything, though!