In all honesty I don't know what to think of the situation. I've been there before and my mom (the other animal lover in my family) and I always felt like they were a fairly good and trustworthy place. We even dropped off baby squirrels there when their nest was destroyed by a hurricane passing through. But it's been a few years since we've last been, so it could be I cannot remember correctly, we were not aware of the situation of some of the animals, or it has gone downhill in the last few years. Or perhaps you just saw some of the animals pens before they were cleaned up, I dunno. I know they have a lot of animals so it may take them a bit to get everything changed out.
But, maybe I'm giving them too much benefit of the doubt. I'm seriously just going off of my own personal experience, since I always viewed them as a fine place. Anyways; your toys and treats sound like a great plan!

I'm sure the rabbits will just love them. I personally would question workers or the owner, it could be the situation isn't as bad as it is. And if it is, then you can go from there.