Chair or Sofa? Which do you use?

If your intention is romance, even occasionally, go with the sofa. Otherwise, chairs are the way to go as long as they are comfortable. It helps if they are also easy to move so you can share the sweet spot with a friend. While listening alone, you can claim the prime spot yourself. With chairs, you will be able to sit more comfortably very close to a friend so you can both better enjoy the music.

Audiobugged, would the correct choice for wax or oil depend on the current absorption characteristics of the room and one's percentage of body fat? Being a little north of the ideal body fat ratio, I prefer wax since it is more reflective than oil. There's no sense in adding an unneeded bass trap in my environment. By the way, I also recommend heavy drapes for both acoustical purposes and to avoid those unpleasant incidents with the neighbors.