I don't mean to stir anything up (I'm a newbie myself
) but doesn't a lot of people here keep cats and birds together, myself included? Personally I have 4 cats and 1 cockatiel I recently adopted, and while I have seriously considered the danger of keeping natural predators/preys together, I've also kept cats and rats/mice for years and never had a single problem. I would think the prey drives of ferrets will be no more "dangerous" than that of the cats', and as long as the owners are well aware of what their pets are capable of and take precautions, I don't see why a simple fact of having a predator type animal should deter you from getting a bird. Just wanted to add my 2 cents in about that since it's a particular topic that greatly interests me :)
As for the other "issues", I lack the experience or the knowledge to make comments and would rather not make any assumptions.