I would like to answer only briefly and also not on every single point .
Have you already selfexperienced all the enumerated possible problems? I think certainly not, but somewhere once read and one to one thus returned. It would be also very sad if.
All problems described by you are known to me very well, however, I have not experienced one of it during the last 20 years. However, so long I already pursue in one or other of my tanks the vodka method.
I am very often on business trips all around the world/europe. Sometimes only few days, but it was already some weeks. I never had with the vodka dosage problems. Defective pumps, Skimmer or lights, yes. Dying fish because one of the "poison fish" also keept by me was died, yes. Corals they fell down and damaged other and themselves, yes of course....., but never one single problem regarding to the dosage of vodka.
Overrun by one of my tanks there will never be. I use in principle the second emergency overrun in all my tanks and I think it a self-evident fact to use such a thing.
Long time problems, I could discover up to now none or I am simply too stupid to see them. Approx. 3 years ago I have taken part in a long time studie (more than a year/14 months) of one of the biggest European forums. From more than thousand participants only two had a problem.
In my article as well as here in the Thread I point several times to the possible risks, what remains to be done? I report only about my experiences. Things I have not experienced I cannot report. Parrot what has written somebody, somewhere once I don't do that in principle. I report exclusively about OWN experiences and not about the somewhere read. And whether somebody what I describes copies or not, is not in my hand. The person concerned must weigh this risk already by himself.