I got ducks a few weeks after I got my chickens, they're the same age as my youngest chicks (16w) and I adore them. They don't adore me, but I adore them!

They're not very social, at least mine aren't. They don't want to be pet or loved on, and if I need to grab one it's a guarenteed chase.
I can't answer on the egg laying. From my understanding is you can get them into the habit of using nesting boxes.. I haven't done this.. otherwise I believe they just lay where ever they happen to be. I also read that they will bury or hide their 'nests' if they make some.
As for water, that's my biggest warning. Water, water, water! I use a blue kids swimming pool, and it's muddy and dirty after just a few minutes. Very messy water buggers. I have a square bucket thing I dump and change out multiple times a day to keep the water clean for my ducks and chickens, but I'll only switch my ducks pool once a day. I usually dump the water in the morning and if it's going to be really hot I will wait to fill it up until later in the afternoon when it's blistering, so they have ice cold hose water to cool off in, and they'll use the drinking bucket to drink until then. Seems to work really well
Living quarters, I don't know the exact space requirements. They home with my ducks, sharing the same coop. Ducks sleep on the floor, chickens take up the roosts. It's 8ftx8ft and I've got 9 chickens on the roosts and 7 ducks on the floor. The ducks prefer crowding together, so sleep in a big pile instead of spreading out,but that doesn't mean they shouldn't have room to move around and get out from each other's feet.