You don't have to turn in quests to receive the rewards! Same goes for permanent dungeons. For both, we're just running off the honor system: as long as an effort is made (the thread doesn't need to be finished), you can assume you've received the reward.

As for previous housing, those buildings do exist! For example, if someone lived with their AU family in Crane City until moving into Dodo house, they can still find that location where they remember it being. Alternatively, if they resided on a foreign campus outside of Crane City, they wouldn't be able to reach that. Let us know if you need any further clarification!