The loft - it's already boarded and has a window, so how about putting a mattress made up as a bed up there, with a lamp, a rug and a couple of bits, and include a photo of this?
The problem is the loft hatch is in the third bedroom, as that used to be the hall. So they would need to have the ladders into that room
Op, it seems you've spent a lot of money in required but invisible things, the full rewire, new windows, and I'm not sure why it cost 1800 to recommission your stove, installing a new one from scratch would cost half that. But anyway. The house must have been in a hell of a state when you bought it,
You just need to tidy it up, viewers are telling you it's the general appearance, and that's the predominant feedback on here.
The video tour shows things like bare bulbs or hanging wires in the upper hallway, stuff half hidden under the table, big marks on the conservatory floor that actually looks like mould in one of the corners, scratched and aged paintwork, things lying about or barely hidden, a table up against the utility room doors so you can't even go in, large cardboard box in the conservatory, random armchair in the third bedroom.
Just tidy it up, don't hide the clutter under things like chairs or tables, even if you put them in your car or the shed, deal with anything obviously marked or shoddy, and add a little warmth with rugs and plants. But mostly make the price reflect the condition and market.