Ok, where to start. I am not a tobacco man for the reasons you stated. But, every now and then I like the likes of an analog and would never go back to the stinkers. So, I made my own. True tobacco flavor. No roses or daffodils. Research - Primary tobacco flavor and smell comes from the molecule Tabanon or Tabanone. The very best is made by a lab in Germany. The concentrate using the greatest amount of the tabanon(e) molecule is DK555, Turkish, and 555. By itself it is to strong for my liking. Enter American Red. It has a nice mild flavor with a chocolate undertone. To mild for me, but nice smell. My Red 555 is a 50/50 mix of DK555 and American Red. BINGO! Great tobacco vape. Then I got to where I wanted an all day tobacco vape. Made Range Blend to fill that hole. To duplicate a flavor you like, without re-engineering the whole recipe, it is important to use the same concentrate(s) you used the first time. That is why I included the supplier in the recipe. TW RL = Totally Wicket Red Label (they have 3 levels of concentrates. Most of us prefer the Red Label over their banner Gold Standard), WIZ and WL = Wizard Labs, and MTB is Mount Baker, HD is High Desert, Vz is Vaping Zone, and LF is Liberty Flight.
All of the brands I use and tell you about are either made by the supplier in the U.S. or UK or resell concentrates from these same class of company. If you look at the Wizard Lab label, on the side running vertically, who the OM is. In think most of theirs are TFA or LorAnn. This is the case with most of the big name vendors. There is another group that makes their own and advertises it, because that is what most serious DIY vapor require. Bottom line unless it is Dekang or Hagen (I probably spelled the names wrong, but close enough to identify them), do not buy Chinese juice. At this time, the two I mentioned are the only Chinese manufacturers that are ISO9000 certified. All of the US manufacturers are ISO9000 certified. Other than the manufacturers, the only other manufacturer on that side of the pond is FlavorArt, out of Italy. Since they cleaned up their act, they are a safe supplier. The new vaping magazine, Vaping Digest, has a piece along these same lines. I deleted my online copy just this afternoon. You can Google it and meanwhile I will see if I can find the address or the link. You are right to be skeptical. I have done a boat load of research for my book as well as other projects and personal safety. The good news, most all of the manufacturers are producing safe product. The ones that don't, don't last and if they do, they get a bad reputation and either clean up their act or make little money and then are run out of business.
Hope I was able to answer your questions and concerns, as well as give you a tobacco vape you might really enjoy.
Eric