Well, door is all sanded down and painted now, and all my stuff is moved in. Had to put a door stop in too or my ceiling would get ruined by the door opening. I have positioned the sofa back to its original place, and although the door doesn't fully open now, it is wide enough to comfortably get people in and out. I'll still keep an eye out for a thinner sofa nearby but it's not an urgent requirement now.
I've also installed the Trendnet plugs which mean I now have internet out there. It's pretty quick too! So I think all we have left is to install the acoustic foam in the door to aid sound absorption, and then we'll have to do some acoustic treatment to ensure mixes are done properly.