The list of allowed foods that matters is here, under questions 2 & 3: http://www.agri.ohio.gov/foodsafety/docs/CottageFoodOperation-factsheet.pdf
Ohio’s law used to be more limited and then they passed an amendment that expanded the list of allowed foods. It appears that only foods that are on the list are allowed. I don’t think there’s a reason why vinegar is not on there, other than that someone didn’t put it on.
Drying your own corn sounds a little more like something they intentionally left off. Even though cornmeal is totally safe in it’s final form, they consider the potential risks required to get it to that stage. Most states do not allow dried vegetables, even though many allow dried fruit.
From the resources I can see online, it doesn’t look like you could produce either of these items. “Mixes” would include cornmeal you buy from the store, but I don’t know if processing it yourself would be okay. However, I could be wrong and I suggest you talk to the ag dept to be sure.