I'd bet that it's not the VG, because you said you don't cough with the eliquid that's 0mg nic, but is 100% VG. I agree with you and think it's the nic causing the coughing.
Also, I would not add alcohol to any eliquid and then vape it. Most people in fact, advise to let any eliquid "breathe" (remove the cap & dropper tip) for a day or so at least, if it has alcohol in it. It needs to evaporate off, because it's not good for you to vape it.
Also, I would not add alcohol to any eliquid and then vape it. Most people in fact, advise to let any eliquid "breathe" (remove the cap & dropper tip) for a day or so at least, if it has alcohol in it. It needs to evaporate off, because it's not good for you to vape it.