Once purchased a HP12C made in the USA calculator from a smoker. Fact that it came from a smoking household was unknown to me at the time.
1. The smell will dissipate, it took quite some time but the smell is completely gone. Don't recall now but it was in the order of months like 3. Soft cover was the primary issue, hard plastic less so. But will say I was not holding the calculator close to my nose as you will with the D7000.
2. Tried cleaning products designed to eliminate smoke odor including baking soda. They helped but are not a miracle cure.
My other concern would be the internals of the camera. If you have been in the house of somebody that smoked heavily white walls turn a bit brown ..... not saying that the individual has damaged the camera through smoking, but I wonder if a good cleaning from Nikon is in order.
Excellence is an art won by training and habituation. We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit. - Nicomachean Ethics