As I'm reading your post I was sitting here working on getting Clifford to relax at the loud thunder we are getting right now. I also have been working on the doorbell thing. He likes to bark at both. For the thunder, as I see the lightening I pet him and keep petting him and telling him what a good boy he is until the noise has passed. As for the doorbell, would work for other noises too, I stand there with treat in hand, tell him to sit, ring the bell, and treat him quick before the barking starts. It has gotten much better, now he will sit and stay until I go out the door, ring the bell and come back in with treat.
If your dog will sit and stay, whenever he starts to nip, like when you go to your crying child, tell him to sit and stay. Giving dogs something they know how to do works much better than telling them stop/don't. I must admit I've given up with the vacuum and my Jack Russel. As soon as I get it out she knows to go to her crate, otherwise she thinks the evil vacuum must die.
Good Luck, it's probably going to take a while.
I'm sure others will have some great ideas here for you too.