I appreciate your suggestions! Actually 3.0 really doesn't use IIS - http://blogs.technet.com/b/rmilne/archive/2014/04/28/how-to-install-adfs-2012-r2-for-office-365.aspx
But no matter, the issues are the same. So when you suggest trying without a verification cert, are you referring to the cert that you upload to WHD? You'd try with no cert uploaded?