I don't think anyone should make a statement prefaced by "if you love your dog". That's very unkind.
What's unkind is to see your dog having ear infections, raised kidney levels, going through multiple surgeries and ignore all the advise people have been given for YEARS now 
Wow Lin, are you ever getting beaten up! I kind of thought the purpose of BPO was to offer helpful suggestions and share mutual love of our bubs. Not chastise its members.
Most of us are not suggesting you do not love your Gracey girl. And the food issue goes on and on. Most of us want to trust our vets as knowing what to do for our bubs. And let's face it. Dogs have and will continue to thrive on all kinds of food sources. There are herders in Whales who feed there working dogs whatever the people eat that night and the dogs are quite healthy.
That being said. Yes, health issues can be attributed to food quality in
some dogs. So IMO it is better to be safe than sorry by feeding a quality food to begin with. However once health problems occur it can be very difficult to find out which component is the culprit. I had a dog with severe protein allergies. He was on quality food and we had to keep trying different kinds to finally find out he could only tolerate venison. All other proteins, chicken, beef, duck, salmon he reacted to.
It is a pain, but you may need to try several starting with Holly's list to find what works best for Grace.
But please be assured we
know how much you love Grace. Here are some much needed hugs and kisses to tide you over while you figure this out.