5. Spending time actually leisurely talking with others once in a while is actually good for your sanity. If the only entity you're ever communicating with for days to weeks at a time is the demon soul inside of you, it might be hard not to start losing touch and eventually your marbles, especially if your inner demon is especially manipulative (nathrezim, shivarra, succubus, etc) and does more than just constantly offer you MOARPOWAH. However, you might be terrified of actually getting attached to anyone, you don't want the Legion to use that against you. Random, fleeting encounters with complete strangers in taverns and the like is the middle ground you need, to see all of these people and (well hopefully, depends on the crowd) remember what you're trying to protect in the first place, to maybe see children shopping with mama in the market place, or to hear some soldier in the bar talking about his old man back home.
2. Your DH needs supplies on a regular basis. They can only carry so much food, clean drink, medical potions and whatever else they want/need at a time. It's pretty realistic that they would need to visit a market every so often, and large faction markets will have the most variety and types of items to choose from. (My DH has been a recluse in the wild for some time, and she is stinky, dirty and has eaten some questionable stuff. This isn't really ideal and a Dalaran doughnut would be pretty flippin nice.)