I fed mine waterfowl starter then duck grower/maintenance feed, with some rolled oats. Plus salad, plus a few peas for treats.
I cleaned the brooder three to five times a day, and had no odor problems. They were in a bedroom, so I would have noticed
The brooder setup that worked for me was a puppy playpen three feet high lined with plastic poultry fence material, with two six mil plastic sheets on the bottom (going up the sides of the pen about a foot). Waterer set on a splash catcher reduced splash by about 80 percent . . . they do fling the water around. Cute little sweeties! Their first swim was at two or three days old in a cake pan, 90 degree F water. After that for several weeks, we went into the tub - 90 degrees, and back into a clean dry brooder so no one would catch a chill. Gave them vitamins and electrolytes after a particularly big day or if anyone seemed puny.
I followed the 90 degrees F in the brooder for week one, then cut down by five degrees a week until they were comfortable at room temperature. Put them outside overnight when night temperatures were above 39 F. Made sure they had water they could dip their heads in to clean their eyes and nares.
No food available without water to wash it down - they will choke. Food and water available 24/7 till about six weeks of age, then overnight (8 to 10 hours only) they can do without.
Some will eat shavings, some won't. I used towels. Some use puppy pee pads, mine ate them. Ditto with shavings.
Ducklings (and ducks, for that matter) can get themselves into the most unimaginable trouble in seconds flat. Heads, wings, feet get stuck, they put everything in their bills, cannot leave well enough alone.
They are the most precious animals I know. I cannot sustain a bad mood around them. They are so cheerful!
They are quite susceptible to predators - they roost on the ground, and mine, anyway, line up along the edge of whatever their enclosure is when they rest. Something could reach through and pick them off if I did not have them in their plywood house or their half inch hardware cloth night pen.
They eat slugs and lay eggs and I put their droppings onto my garden beds, don't have to compost them first. The plants love their fertilizer!
Free ranging success will depend on your environment - if there are dogs or other animals to keep predators away, or some other means. Daytime around here, we have hawks (which generally only take ducklings), coyotes (yes they occasionally come out in the day), foxes (ditto), and domestic dogs and cats. Giving them something to look forward to (dinner, treats) will help get them to come back in the late afternoon.
They can be very sociable, but that takes time and effort on the duck keeper's part.
Many breeds don't get broody, but there are always exceptions. They take 28 days (except Muscovies) to incubate, but there is an entire skill set involved there. We have quite a few experienced people on the forum for that. There is a difference in humidity management, if I recall correctly.
Anconas are lovely. You may want to have a breed that is of concern to the American Livestock Breeds Conservancy, or one that you just like the looks of. Aside from wandering around, were you thinking of traditionally ducky, light, dark, small, large, loud, quiet?
