Here’s a quick update on the plugins. Once I knew I had the ability to deactive them safely, I tried turning on each of the plugins individually to see if I could blame one for my troubles.
Each one returns this warning and then the header error returns for urls that don’t contain the WWW.
“The plugin generated 2 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.”