It kind of sounds like she may just be having an anal gland issue. She may need them expressed. You should call the vet and make an appt to have it checked out.
I don't know if you checked out the breedlist.com link. If not, there are a few breeders in Virginia which isn't too far, there's also a listing for Arkansas.
Oil and vinegar by themselves are fine, some of the other stuff they add to dressing may be harmful, such as onion or garlic, but if it may have only been a few licks, I wouldn't worry.
When they eat mostly wet food, they don't need to drink as much, so this may be the case. Also, the diarrhea could be from more canned foods, or the fluids. If she's not dehydrated, giving her the extra fuid could cause the diarrhea because her body is trying to get rid of the excess.
It's a word to describe inflammation of the mucous membranes of the nose and sinuses,it may be acute or chronic. More than likely it may have just been a minor irritation or infection. She may have been dehydrated because she wasn't getting enough water, the IV fluids helped her to get back on...
Try getting him to play with a feather teaser or laser toy. Get him to run and jump around at least once a day if not twice. I have found it's the best way to get them to exercise.
Most cats are full grown by about 1 1/2 years. However, there are exceptions for certain cats, and certain breeds. A pure Breed Maine Coon can grow until they are 4-5 years.