Haopee, prevention can be the best medicine! Sometimes if you can ward a dog off before they get to the unwanted behavior, you can improve things.
I think I am making progress with Misha. One of her worst behaviors was her fear when injured. It is awful trying to tend to an injured dog who is afraid of you touching them.
Recently, she hurt her paw. For the first time, she allowed me to carry her back into the house without fussing. Then, she allowed me to touch the injured paw. I massaged it for several minutes. She tolerated it all. It made me feel really good, because she trusts me more than she did 6 months ago.
I'm making great progress with her barking, too. Several times recently, I have put out my hand and said "stop" firmly and she has stopped in her tracks. It's similar to what you did with Chooey with the nipping.
It's a nice feeling when you see many weeks and months of work start to pay off.