My thought is that while there may be much validity about quinones and oxygen, it is far too simplistic to imply that quinones alone are responsible for the beneficial actions of so many widely varied supplemental items. Nature works synergistically the same as our bodies do, and I have no doubt whatsoever that the actions of many of the items you list go far beyond merely donating oxygen.
Take oleander for example, something I know a thing or two about. Over 500 compounds have been identified in oleander so far. A large number of these compounds have been found to have anti-cancer properties, and as time passes, even more are being identified as having differing anti-cancer and immune boosting properties. On the other hand, none of them singly are nearly as effective as the combination of compounds one gets when an aqueous extraction is made from oleander (or, in the instance of the new oleander pill in FDA trials at MD Anderson, when a liquid carbon is used for extraction).
Several different mechanisms have been identified that help oleander fight against cancer. First of all, it is a tremendous immune stimulator, reportedly having fully six times the immune stimulating activity of the most powerful patented immune stimulators when tested in European studies in 1986-87. A strong immune system is the body's first line of natural defense against cancer, and cancer is almost always found only in the presence of an impaired immune system (it is also virtually always found only in the presence of an impaired liver). Oleander also enhances and induces normal programmed cellular death via apoptosis and autophagy. And there are likely other effects as well. I don't think all of the actions can be attributed solely to oxygen. And, insofar as the dose is concerned, oleander extract has been tested by the FDA for toxicity and has been used in thousands of patients by Dr. H. Z. Ozel in Turkey and others over the past 40 years.
I would assume that the same would be true of black seed oil and other potent cancer fighters. If everything came down to quinones, then it would seem to me that all of the substances would be equally effective against all cancers depending upon the dose. That is not the case, as is evidenced by the fact that black seed oil (Nigella Sativa) and oleander are particularly effective against pancreatic cancer whereas many other substances that are effective against some cancers are not.
No doubt that oxygen is a key in fighting cancer, and is a key component of many supplements and protocols. But it is not the sole key found in all of the things that fight cancer.