Sorry I cannot answer your specific questions as I do not know about, nor have seen any research on, aflatoxins. I did find the following Earth Clinic post from someone regarding the afalotoxin issue from Hulda's book:
12/01/2008: Pamela from Houston, Texas replies: "Hi, I am not a specialist but if you had not read the book "Braggs Apple Cider Vingar" I would suggest it. The authors are long time users of acv and had very healthy lives. The book explains the ins and outs of how acv works. One the best things to me about acv is it helps to calcify the body which leads to a lot of differ health problems. A person's body gets hard as they start to age because of this. Touch a few really old people and you can tell this. There are so many other benefits from acv. And I have received many from using it. In Dr's Hilda Clark book she suggest putting 1/8 tsp of powder C in acv to keep the aflatoxin from forming in it and keep in the refrigator. I think that is why sometimes some people have problems with acv because they are sensitive to the aflaxtoxins or they are using a none organic brand of acv. Hope the book helps you it did me and is a good read."
After doing a quick google search it appears that the aflatoxins are basically molds that grow on nuts, breads, etc. People who have a hard time with them are those that are deficient in certain types of enzymes or possibly liver issues. I take potent enzymes with every meal and use NAC to help my liver so I have not noticed any issues with this. I've mainly noticed the positive cleansing effect on my digestive tract.
Again, I think white vinegar is usually discouraged for people fighting yeast overgrowth, but raw organic apple cider vinegar is encouraged, especially in the Body Ecology Diet. On most issues, you will find differing opinions going both ways. I have heard some people say ALL vinegar is anti-fungal. I trust my body and god-given knowledge (intuition) more than what others say. All I can say is that it has definitely helped me, just like raw garlic has. That would be my best advice: go with what your inner-self tells you is right for you now at this time.