I hope your post is a troll and I am your first victim, I would hate to think you could be so misinformed.
Iodine 131 (the radioactive version) is not more chemically toxic than iodine. Radioactive iodine causes thyroid cancer because of the ionizing radiation causes chemical changes and destroys/alters DNA in the surrounding cells. Plutonium is about as chemically toxic as caffiene: http://en.wikipedia.org/wiki/Plutonium.
Nuclear contamination is not easy to deal with. If it were, do you really think a facility as sophisticated as Yucca mountain would be necessary?
I hope your last question is rhetorical. There is no viable way to compare the relative damage from two alternatives such as this. If all of the batteries are properly recycled, the nuclear solution is probably better. but what happens then the owner of the nuclear battery falls overboard and he and his hearing aid are eaten by fishes?