I can speak for the urinating part but what I will tell you is that you need to do a lot more research on iodine as the unsafe limit you speak of has been debunked a good while back by many studies and also the simple fact that many folks myself included are taking 100 mg or more iodine daily. Start by reading the "Iodine Answers" link at the top of the forum page http://curezone.com/faq/c.asp?a=13,281,2962. Lots of very useful and educating answers and links there.
See Cougar's excellent post above. Also check out "Iodine Answers" at the top of the page.