First... there is a LOT more to cigarette addiction than merely nicotine -- in fact it seems to be mostly a psychological addiction, with a varying physical dependence (addiction isn't the right word for dependence on something that isn't harmful in itself) on nicotine (and all the other alkaloids). Just observing your own interest in a cigarette is no way at all of determining your proper nic level, though it can be a *clue* -- not the whole story. But there are many, many things that can "trigger" a cigarette craving; chemicals being only one of those things.
the occasional thought of a smoke isn't really a craving it is more the odd passing thought. I completely agree with you regarding the benefits of nicotine- I have been somewhat of a protester over the years of the foolish rules that came in to play regarding tobacco use so did quite a bit of research regarding it. I did quit years ago when my kids were little, I gained 30 lbs was anxious and always missed it. I cannot say this is true while I vape and I do intend to prevent a return to tobacco if at all possible. I also take every opportunity to promote vaping unfortunately our patients did get their smoking rights reinstated but the health board where I work (soon to retire) will not permit vaping or e cigs of any nature - -more political bs - at present BUT I have hope that because vaping and mixing your own is so easy that it might not be as easy to attack as tobacco
Secondly -- unless you have some physical disorder that makes nicotine risky (anything in which constricted blood vessels could be a problem -- kidney disease, cardiovascular disease such as hypertension, and probably others -- maybe glaucoma?), then nicotine won't hurt you. If you aren't getting nauseous, jittery, stomach pains, unable to sleep, or possibly headache -- then you're not getting too much, and it's really nothing to worry about. However if you suffer constipation, extreme anxiety, or again, possibly headaches, then you might not be getting enough. Headache can go with either too much or too little, because of the role that constricted or dilated/engorged blood vessels in the head can play in headaches -- migraine usually means they're dilated/engorged, and NEED to be constricted, but if they're too constricted, it might impede blood flow to the brain.
There's no particular reason to just *automatically* reduce nicotine, just because so many do -- whatever level is right for *you* is what you should aim for, regardless of what anyone else does -- as you noted that you reduce when you use a device that delivers more. But nicotine can actually be a very useful substance, sharpening mental acuity, and potentially even helping to prevent/delay the onset of cognitive dysfunction (dementia of various kinds).
Andria