Hmm… without a proper diagnosis, it’s hard to know what is causing the wheezing. It could be an infection, like pneumonia. This would require antibiotics. While pneumonia is serious, there are also much more sinister things that could cause the wheezing. How old is she? Do you have any idea? If she is unspayed, then something to consider would be cancer.
The fur loss might be due to the change in environment. If her ears are itchy though, I would have her checked for mites. There is usually skin thickening, as Bam mentioned, but it’s best to be safe than sorry.
I would not be concerned about red urine. Plant pigments can cause urine to be orange or red. As Bam said, you can check for blood by pouring some hydrogen peroxide on the urine to see if it fizzes a lot. You should start transitioning her to a better diet. You are switching from alfalfa hay to grass hay, which is a good start. But you will need to adjust the other foods she is eating as well. Pears, apples, and blueberries are OK to feed in small quantities (1-2 oz per day). Carrots are the same, only small amounts. And, as much as she loves corn, it isn’t good for her. The casings around the kernels can obstruct the intestines. The others are OK, but I would suggest trying leafy greens like romaine lettuce, etc. New foods should be introduced slowly, of course. Here is a guide to safe fruits and veggies: https://binkybunny.com/bunnyinfo/veggie-list/