First and foremost your breeder is an IDIOT!!! I don't like to use that word as I do not like to insult people but WOW!!! Your fault because you changed her name, and the pine trees are the reason for the rash? WOW!!!!
If your dog is happy overall isn't that the best we can ask for? The games, the competitions, the shows...some dogs do enjoy it, but its often more about us than it is about them.
The beauty of dogs is they are all individuals and that means sometimes they have personalities that just don't fill every niche we want them to. Some dogs are more aloof, less affectionate, less playful and more independent. She loves you and is happy to see you when you come home but she just isn't going to go on about it like a Golden Retriever who wants to keep celebrating your return for the next hour.
I don't want to sound defeatist, but sometimes a dog just isn't interested and trying harder to make her like it can backfire. Pressure to perform can shut her down more. We have a Rottie who is incredible in his obedience, but the second I try to record it on camera he completely shuts down. There is nothing I have figured out to get him over it. He just doesn't like the camera - I think he thinks its a huge eye that keeps following him around - creepy!!
I think a visit to a holistic vet would be of value. She could have an impaired immune system, an allergy or a low level inflammation. If you weren't feeling good and you were itchy, or just not quite right you may not want to participate in life much.
Sometimes a highly sensitive dog can be very shut down if they have been over corrected at some point in time. They stop trying, they stop having fun. Not saying that happened but it can result in this type of behavior.
It might just be that she doesn't want to play the games you want to play. It sounds like balls are key to finding her inner puppy, so that seems like your best bet for getting her more excited about things.
What are you feeding her? Grain free?
Love Them & Lead Them,
~Elizabeth & Doug
Dog Training the Way Nature Intended