IanTurner - 7:40 am on Mar 6, 2013 (gmt 0)

You didn't misread - the page without the parameter just has it set to 1 by default and doesn't need it in the url, so basic internal links are without parameter.

However, I too have a concern with your item 2 as the pages with the parameter may well generate external inbound links and in my view the value of these links would be lost if the page was noindexed.