I would like to have my pagebar run across the width of the site as in the primary navigation of the following site:

http://greglaswell.com/

Seems like I would do this somewhere in bfa_header_config.php but would obviously like to get as close as possible using CSS.

Thoughts?

The trick in doing this is that WP generates a page dynamically, so if you have three pages today and have it centered and add a new page tomorrow, it could be messed up.

Have you tried %page-center at ATO->Style & edit HEADER AREA-> Configure Header Area?

I changed the language in CSS.php from:
div#menu1 {
border: dashed 1px #ccc;
}

to:
div#menu1 {
border: dashed 0px #ccc;
background: #F7941D;
}
to remove the dashed border and change the background of the page bar to the desired color across the entire page width.
Hope this helps.