i smoked for 28 years, i originally started vaping in an attempt to quit but i LUV vaping so i intend to keep on keeping on. i still want to get away from nicotine consumption and i know that it is cheaper to buy e juice, i am learning how to diy, do the tobacco flavorings contain nicotine or are they nic free? help please and what is the difference between vegetable glycerine and standard glycerine?