I would have to say that everything you are thinking about and concerned about is pretty typical being new to vaping... Im new to the forum but have been vaping for about 9mo. now, after being a pack-a-day smoker for about 14 years. I was free of cigs within the first few days of vaping. When I first started I had many similar feelings and questions. When we first start vaping we do get a bit overzealous over it... Vape all day like its a new toy, vaping inside everywhere, taking extra huge drags, etc... the nauseous feeling is normal at first and you will adjust, you will also find a more balanced rate of vaping once the new hype of it wears off a bit

I would say that 18mg was good for me to get me off cigs, I find that at 18mg my vaping sessions are a shorter, and I get my fix a bit longer... If I step to 12mg I just end up vaping more juice to reach the equivalent. Your body will adjust fairly quickly, it will get used to the absorption rate and you will get that "fix" feeling on your first or second drag, because your brain starts to get used to the timing of everything and give you that "fix" feeling quicker. When this happens and the hype of using your device subsides a bit, you will stop over-vaping as much. Don't get me wrong the HYPE of trying juices, devices, etc may only increase

im just saying having your device in your hand all the time will chill out a bit

Regardless even if your vaping a bit more nic right now your cutting out 1000s of nasty chemicals and tar etc etc, so even if your nic intake is a bit more in the beginning, its a fair trade off to kick all that nasty stuff out... I recommend you do whatever works right now to be successful staying off the cigs, and then worry about your nic levels, etc... Nic is Nic, 6mg-36mg ur just gonna vape less or more to get your fix. The more I read, watched vids/reviews (grimm green, etc), and dove into vaping I found it helpful for me be successful. I personally have no intentions of reducing nic or getting off nic right now, I started vaping as a safer alternative to cigs, not to quit. I eventually may cut out the nic but I will most likely vape 0mg forever thereafter. I can tell you I feel much healthier, breathe better, taste my food now, can smell the grass, sing, run, don't smell, save a lot of money, don't worry as much about cancer, etc, etc. Experiment with juices, different attachments (drip atomizers are my preference), etc. When I started I bought a standard ego, then my first VV Ego-Twist really opened up a lot of doors being able to change the voltage and fine tune how I liked my vape. This was also helpful with not over-vaping. Once I got a really satisfying vape with my combination of juice, device, attachment, etc... I became less dependent on just the nicotine satisfying my fix alone. For now don't make your vaping sessions shorter, just try taking shorter drags, or the time between drags longer, and keep experimenting to find a really satisfying vape for yourself

If you still haven't adjusted well to 12mg, Again the bump to 18mg should satisfy your fix quicker, last a bit longer, and feel a little more equivalent to a cig "quick fix". Will also help you as your body adjusts to gauge roughly how many drags you need to get your fix. Trust me, first 2 weeks I was spinning like I was 13 smoking my first pack again

GL!!!