Whoa just read through this entire thread! You've had a pretty crazy time!!!
I've had birds my entire life, and one major thing I learned was that they DO NOT do well with anesthesia. I lost a cockatoo who developed a tumor on his stomach, we decided to go ahead with letting our vet operate to remove it. The vet warned us that the anesthesia alone could kill him because of birds' fragile respiratory systems, but we decided we had to try before putting him down. Turns out the tumor had already taken over his organs, there was no chance of survival. Our vet is one of the top vets in the state, so we knew it wasn't her lack of skill. Soooo that's probably why the U of Tennessee probably told you it was risky.
Also, you might want to invest in a good book or two for dealing with chickens. The forum here is a great resource, but we're not all trained professionals -- so take the time to get information from trained & educated resources when it comes to caring for your flock, especially during these emergencies. I would hate for you to follow bad advice (but said with good intention!) and lose your hen! I'm so glad you took Rosey to the vet before trying to operate by yourself.
I hope she improves quickly & you never have to go through this ordeal again!!!