No.
Cigarettes do not contain propane. Propane is a flammable gas. Most cigarette lighters contain butane (though some refillable lighters use a naptha or petroleum-based lighter fluid), and that is used to light the cigarettes, but you are not constantly breathing that.
Yes, If you smoked 5 cigarettes chances are high that you will get addicted to the cigarettes.
The smoothness of cigarettes varies a great deal as far as taste goes, and e-cigarettes are not all the same, but generally e-cigarettes that I have smoked seem to be smoother than cigarettes.
No. tobacco is in cigarettes.
cigarettes
petroleum refining is petroleum refining
cigarettes
The drug that is in cigarettes is nicotine.
There are no fat in cigarettes...??
No nutrients at all in cigarettes.
Cigarettes are not gluten free. A gluten substance is added to cigarettes for flavor.
Something that contains no petroleum is petroleum-free.