By your definitions I'd have to say major problem. I know that I am having trouble with nic levels. I go from 24 to 18 to 14 mg. So too much or too little depending on my reaction and the day. It's well worth it though.
After about a week of vaping I starting coughing when I was done. As I understand it, this was my body getting rid of some of the crud in my lungs from vaping. The coughing lasted about 3 weeks and then it went away, since that time I have had no other problems vaping except when I have done too high of a nic level and I have gotten heartburn and a headache.
The coughing is your body getting rid of the crud in your lungs from smoking. I know alot of smokers, when they quit, start coughing alot. So much that most just go back and have a cig again just to stop the coughing.
I think nobody linked to that thread yet: Understanding Your Symptoms While Adjusting To Vaping
Skin peeling sounds indeed like a PG problem, do check out this thread: http://www.e-cigarette-forum.com/forum/health-safety-e-smoking/62464-effects-vaping-skin.html
After 4 years of smoking and 2 months of quitting the symptoms I am noticing that came from smoking are the lungs still ache a little bit and I still have a little bit of a smokers cough but it has lessened a lot.
Symptoms I am having from vaping are dry mouth with 100% VG that's about it.