Your Billing email is stored separately and stored with your billing infomation. If it changes you need to open a ticket with the help desk to Billing and they will help you.
Your pages are .htm files and not .php files. Did this ever work for you?
You need add the following to your .htaccess file for PHP includes to work in .htm and .html documents.
>AddType application/x-httpd-php .htm .html
I see that you are using FrontPage. Every time you install or re-install the FrontPage extensions it modifies your .htaccess file and you will have to add this line back in to use PHP includes in those documents.
Sorry Paul, I just don't see it. I've been through the script several times. The problem is you are not calling a function Wordpress is using the -image- to trigger calling it somehow.
From their readme file.
I was looking at the plugin source and all the functions within the plugin are using the php if clause so maybe it will just die gracefully if not activated.
Deactivate it on your site and see what happens. You can always get back to the admin panel with the your-blog-address/wp-admin/