Claims Based Authentication for Extended site

Hi,

We use SharePoint 2010 farm with Windows Authentication. Our default web application for user's content is: "SharePoint TTT Default - 80". We would like to Extend this web application and use Claims Based Authentication (FBA). I read this guide:http://donalconlon.wordpress.com/2010/02/23/configuring-forms-base-authentication-for-sharepoint-2010-using-iis7/
but have some questions:

1. Should we first extend web application “SharePoint TTT Default - 80" and then configure Claims Based Authentication for that site?
2. Is it necessary to accomplish STEP2 to "Configure Central Admin Web site to use SQL Membership Provider" and STEP3 to "Configure Secure Store Web Service to use SQL Membership Provider" from the guide above as we want FBA just for Extended "SharePoint TTT Default - 80" web application?

Thanks