There may be some kind of 'Easy Home Designer' type program that works like your set designer idea. The catch would be if it can export a model format that Poser could import and then getting the scaling right inside Poser. Poser is a "hobbyist" application. You really do need to tweak and twirl and learn quite a bit to really start getting the most out of it. The Sims is more a "consumer" application. Someday perhaps the two types will merge and we'll have some of Poser's artistic ability with a more approachable interface/lower learning curve.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken