I wouldn't leave the bandage on if I was going to be gone very long. I have one now also that is seriously badly bent out... totally flopped over. Phoebe's lone duckling. I can't leave a bandage on him because he has 24/7 access to bathing water. I am thinking I will just trim that wing and let it go.
I honestly don't believe its the type of food or genetics. I've hatched too many with no problems, and mine all eat the same food as each other, and this is the first one. I think it has more to do with the amount of food, rather than the type of food. This one of mine has always been more of a loner, and I find him at the feeder much more often than the others. Even after Malibu's hatch a couple weeks after this fella, he hung out with momma Phoebe and the older ducks, as much as they allowed, but they shoo'd him off a lot of times too, so he would go sit by himself while momma had her time with the older group. Malibu pretty much takes care of him along with her group now, and they have all integrated fairly well. But I still see this little guy eating a lot more than the others. He also doesn't get in the water much. Even when they sleep in the water, for a long time, he would sleep by himself in a small space between the pool and the fence. I believe its just an individual growth thing, until I see proof of something otherwise.