I don't know about the iodine content, but I imagine it's like anything else, don't go crazy on it and you'll be fine.
On another note, I love me some kelp noodles. Spaghetti squash just did not work for me and I missed the mouth feel of noodles. I ordered a box of twelve packages from Sea tangle. There is one weird thing about them, or at least the brand I use. Boiling water does not make them pliable, but anything acidic will. So if you're adding it to a tomato sauce, no problem. Otherwise just add some vinegar(or lime juice) to the boiling water.
Not that you actually need to boil them, they're edible right out of the package, but have a odd texture(to me). Not hard like pasta, but sort of crunchy(for lack of a better word)? I can't really describe it. But delicious nonetheless.