Firstly, your house is beautiful and secondly anyone looking at that design of house knows that the third bedroom is technically a box room.
Can you "fake" a wardrobe, ie if it is free standing one then you could just cut out the back and slot it around the bulk head? In these type of properties lots of people have a bed built into the space over the bulk head so you could suggest that to buyers. My neighbour built a desk along that entire wall.
I think the other issue is the lounge, so if it were my house I would have the sofa where the tv currently is and the tv to the right of the fireplace.
I think by having the sofas pushed against the wall it suggests the space it tight, it isn't it's just the way it is presented.
Do you have all your clothes in bedroom 2 as I can't see a wardrobe in bedroom 1.
I think people lack imagination when it comes to viewing a house and need things suggesting to them as to how it could work for them. Like I said, your house is lovely, beautifully decorated and maintained.