Blergh What sort of house is that big with no sections? It's like trying to be studio but having the space to not be one.
I was looking at the partially-outside staircase as well. I confess to having done that myself, but by accident! If the creator wants a staircase that is flush against the wall, he or she would have to lose the railings. Try an open staircase. There are enough of them around!
Actually, some of my houses' layouts have looked a little like that (minus the partially-exposed staircase) if I move a Sim for the first time into a larger lot. (If I envision a family Sim having a big family, or if I want to put a large orchard or garden on that lot, I tend to skimp on the niceties of house decor at first.) But I fix that baby up as soon as the Sim gets a little money. And I certainly wouldn't sell any of my houses that way, if this is a pay item. I don't even take PICTURES of the house that way!
And a dash of bright color here and there can be your friend. If I actually had to move in a house like that, I would get depressed by the dreary color palette really, really fast. Some of those colors remind me of the 70's. And even if one used those colors back then, one would at least have a dash of orange in there! Or lots of ivory or off-white.
And re the prom dresses ... whatsamatta with those dresses? They would be quite the rage ... if you were around in 1963/64!
My Tammy doll (think Barbie wannabe) had lots of dresses like that! But even then, you would never use that material for prom dresses. You'd need chiffon or taffeta or sparkly stuff. And you'd have to get rid of the flowers!