I would completely LOVE having a crafting room that is affected only by the furnishings in it. A garden room for pots as well. It is hard to keep gardening up when you are doing smithing and use the fire etc for that craft. A living room that could be decorated any way you wanted with no regard for elemental influences and a bedroom for decorative purposes as well. I dont want my bed in my living room. It is just too odd. I would not mind having elemental influence on those rooms but separate from crafting. That way you could put garden pots in the bedroom if they did not give a separate room for that.
Being able to sit or lay on the furniture would be wonderful as well.
I do not think any of this would be simple. After the whole server move debate it has been made clear that not much about the game is simple. These mog house changes would be great though and there are a lot of us that would really appreciate it.