[matese]

Great that he gets along with dogs, it is a safety issue for him if he was not.
Cats, you do not have any, so there's no problem there.
Small children, if not raised with them, yes, many yorkies get nervous around rambunctious young children.
Aggressive towards strangers, I believe with more socializing this could be overcome. When you get company have them ignore the dog, let the dog come to them, give your guest a treat, when your pup calms down have your guest offer him the treat, do this with any company that comes to visit you.
I had a girl, I raised her from a 8 week old puppy, my family consisted of mostly women, my girl was aggressive towards men, she would nip the back of their shoes when they entered the house lol. Once she got to know them she was ok. I would do as I have suggested to you, over time the sneak attack of nipping at their shoes stopped.
Loud noises, the only loud noises my girls were afraid of was thunder and fireworks, which most dogs are. My adopted boy (now 5 years old) is also afraid of these noises, plus gun shots and nail guns. If these are the loud sounds that he's afraid of you can try putting a ThundShirt on him. I have not used one, we do have members that have said a ThunderShirt has helped their dogs.

Is he neutered
Is he micro chipped