One thing that drives me nuts is just how many things need to be usable, but aren't. The deep windows with built-in ledges in Eco Living would be perfect ways to live well in less space, need less furniture, because you could place potted herbs, bookends, radios, and many other things on them...except you can't. They are merely stickers on the wall, just as the bay windows are. Disappointing not to be able to have potted herbs in a sunny bay window in the kitchen. That window-ledge is just a flat sticker, an optical illusion.
The little shelf on a murphy bed? They can place a decorative candle on it, but we can't place anything on it at all.
And radiators are mere decorations without the Functional Radiators Mod but at least it's there.
But too many items are just like stickers in a sticker-book, only appearing as if they could be used for anything.