It really depends on the breed of duck you want to house in the hutch. I'm guessing it has a wire bottom? I would only use it for ducklings and bantam breeds.
I wouldn't use it for Medium or Heavy breeds. The wire will hurt their feet and they'll develop sores all over and they won't stand or even move for that matter.
Other than the wire flooring I'd say it would be fine. I have one with a wooden floor for an Indian Runner and a White Crested. However, they never use it. They prefer to sleep outside on the grass. I'm assuming it will get more use when it snows.
Yes, that is what I am currently using. Mine is a 4X6' with 3 separate "rooms". It has a wooden floor, not wired and I use it for my 2 Rouens, plenty big enough for them. We did have to modify it slightly, but not much! I will post some pictures later if my camera is nice to me!
I use a 4 room; wired floored rabbit hutch for my call ducks (3 ducks in all) during breeding season. One room for feed, one for water, one with nest boxes, and the last one has straw covering the bottom so they can rest their lil ducky feet. So I think it should work for lil babies.
Plastic poultry fence on top of the wire floor might help. For brooding, someone on the forum said she uses towels, which dry quickly and are soft on their precious little webbed feet. Good traction, too.