Thanks Grizz, it is very thorough and easy to read.

I have one comment though:

She says: "Therefore, if you are already hypothyroid, taking selenium supplements while Iodine deficient will make you MORE HYPOTHYROID."
I don't agree with this. I think what happens is this:
When you're hypothyroid, you're low in Iodine (because that's the reason why you're hypothyroid). If you're also low in selenium, the body will not try to find more Iodine so hard, because that will only damage the thyroid. So TSH does rise, but not as much as it would with sufficient selenium. Also, a goiter is much rarer, for the same reason: the thyroid doesn't expand because it really doesn't want to attract that much iodine.
When you add selenium in a situation as just described, than the thyroid will start looking for iodine much more aggressively. TSH will rise and you might even get a goiter (depending on how bad the iodine deficiency is).
This might look like you're getting more hypothyroid, but it isn't: you're just as hypothyroid (maybe even a little less if the thyroids strategies for finding iodine are successful), but you do have a higher TSH en maybe even a goiter.

So, you could say that selenium can cause the TSH to rise and goiter to appear, but that is blaming the wrong guy: selenium is just protecting the thyroid from damage. There is no guy to blame: the cause is de iodine deficiency.

TSH really really doesn't tell you anything about what status the thyroid is in.

High TSH just tells you the thyroid is looking for iodine.
Low TSH can actually mean two things:
1. Everything is okiedokie
OR
2. The thyroid gives up on looking for iodine, and it now lowers TSH to stop looking for more iodine. In this situation the thyroid switches from producing mainly T4 to producing mainly T3 because producing T3 is more cost effective. In this caue a low TSH means that the thyroid is quite desperate for iodine. So treating this as a disease of access thyroid hormone is just wrong.