I think the corral would do better as a size changeable building like roads, bridges and farm plots. Then you would build a fence around the animals, which would make more sense than the animals being intelligent and accommodating enough to stay in one open spot. Use umhk to place the gate, have it move along the fence instead of having a 'facing' so you can put it on or next to a corner. Maybe have a door as a component to use for the gate,along with the raw material for the fence. Would also be great for if you want an actual 'zoo', with enclosures instead of everything crammed into cages.
A nursery would be good as a room plotted out from a piece of furniture, maybe a bed. Any containers (especially chests) would be used to store toys for the infants/children to play with (when kids do play with stuff). Maybe you could 'assign' toys so that your artifacts don't end up as playthings. Probably only babies for the nursery, since dwarf children can actually be a productive part of dwarf society. Hmm, a 'only children harvest' option would be interesting and free up your adult dwarves to do more important things. The kids would probably be pretty unreliable though.