There are a number of mistakes in your 'article'. First, I don't know where you got the info that "Vit C can displace B12". Higher dose Vit C can hinder the absorption of b12 in the gut if taken at the same time (or within an hour). However Vit C has been shown to protect those with a B12 deficiency (pubmed "Megadose effects of vitamin C on vitamin B-12 status in the rat.")
Second, the iron issue. You say excess iron can cause heart problems. From National Center for Health Statistics and Centers for Disease Control say "reported that high transferrin saturation levels are not associated with an increased risk of cardiovascular heart disease or myocardial infarction. On the contrary, it was found that there is an inverse association of iron stores with overall mortality and with mortality from cardiovascular disease." Also, Extensive studies have shown that overall the uptake and storage of iron in humans is efficiently controlled by a network of regulatory mechanisms. Even high vitamin C intakes do not cause iron imbalance in healthy persons and probably in persons who are heterozygous for hemochromatosis. . .Again, you're wrong.
There are some other mistakes in your 'article' that I don't have the time to get into at the moment. However, there are no dangers from high dose Vit C, period. And there are MANY more advantages to taking Vit C than you list.