Probably true, on nic usage; it does concern me somewhat that people are vaping a great deal more, inhaling a great deal more vapor, to get the same amount of nic. Once I figured out the right nic level for me, I haven't had any side effects from the nic at all, but a good many, none of them pleasant, from the PG/VG. I've personally not had any ill effect from flavors, but the potential for that would also increase, as the amount of vapor increases.
Andria