first off, that low dosage can and probably will produce a detox symptoms that are exaggerated. what exaggerates them is not having enough iodine, believe it or not. since the 50mg iodoral are not available (local pharmacy said the canadians bought them all???), i assume youre talking the 12.5mg caplets. this means youre up to 50mg and i tell everyone 100mg is a minimum to start.
you are right about the salt helping the hives. hives are a histimine reaction and that is a sign of dehydration and the cure for that is salt. dont ever shy away from salt. you need it to get water into the cells.
you should not take the flushing kind of niacin. niacinamide is the type to use.
your selenium should be selenomethionine only.
if you are having water retention with the increase in salt and water then potassium is a problem, and it probably always has been for everyone. get one of those little blue shakers of nusalt salt substitute in the store. not for long term use because of the contaminants in it but just to experiment. i dont like the taste. just put a quarter teaspoon in a little water and slam it like a shot of rotgut whiskey and chase it with something, some juice or milk. do this during a meal or it can make the stomach ache. youll know if its doing you any good after a couple times of that. you can do that with every meal. if you want to continue then get the pure stuff at bulksupplements.com.