We all took Iodine before Mag Malate so what happens to someone Iodine deficient I can't say.
As for doses;
Two open trials have reported significant reductions in measurements of myalgic pain, as assessed by tender point index, in fibromyalgia victims supplementing with magnesium and malic acid. The dosages have ranged from 300 to 600 mg of magnesium and 1200 to 2400 mg of malate, with most symptoms improving in approximately eight weeks.
As for buffered C I don't take it only Ascorbic Acid, zinc is not allowed unless you are Hg free.