First off Welcome to Yorkie Talk!!
Sounds like a really good list and CONGRATULATIONS!!! on getting your new yorkie. I would suggest instead of getting a collar to get a harness because pulling on the collar could cause collapsed trachea if he pulls hard on his collar.
I got Dino's ID tag at pet smart and it was about $6-7.
Happy Birthday BTW!!
That must be the most amazing birthday gift ever!!
About the changing of the name, I don't believe it would be cruel to change the name, maybe you could change the name to something that sounds similar to the name he has, like if his name is Danny you could try Manny, because they tend to recognize just the sounds of the syllables and not the whole word itself.
A friend of mine found a dog that was about 4 years old and after 2 months he started responding to the name so he may just get used to it.
Also don't feel bad if he does not warm up to you at first, it is going to be a big change for him, so try to take things slow and not expect too much from him. He will eventually warm up to you and things will get better.
Once again Congratulations on getting your new Yorkie and Welcome to Yorkie Talk it really is a wonderful community with really great people.
Oh Yeah, there is one rule here: YOU MUST POST LOTS OF PICTURES