I had trouble with where to put it because i can't see the form except in code view. I tried it several places, inside the form and at least once outside the form (I think you saw that one in Post #3) none of which worked. But I will put it in again and attach it shortly. The problem I'm having with where to put it is partly because the whole form section is about billing, which I can't even see when going to this page while testing the checkout page.
Attached is the checkout page where I tried wrapping the comments field in a div like the other form fields but deleted the validated-field copy since it is not a required field. Still doesn't show up when I place a test order and hit checkout. In fact, the only time I got it to show up on checkout.php was when i placed it in the cart_wrapper div into it's own separate form tag.