i would strongly advise that you not edit any files from inside the dashboard. most of the files there are thematic core files which you shouldn't mess with. you will be better served editing a functions.php and a style.css and then FTPing them to your site. MOST files can be editing from your child's functions.php via the extensive hooks and filters of thematic. if you have made extensive changes via the dash i would even suggest reinstalling thematic.
add this to your CHILD'S functions.php and you will get a home link in your page menu
function childtheme_menu_args($args) {
$args = array(
'show_home' => 'Home',
'sort_column' => 'menu_order',
'menu_class' => 'menu',
'echo' => false
);
return $args;
}
add_filter('wp_page_menu_args','childtheme_menu_args');
http://developing.thematic4you.com/2010/04/breaking-things-to-fix-others/
according to the above link: if you are using thematic 0.9.7.something you now have to add the echo => false parameter to the menu arguments to get the ul element to have the .sf-menu class, the lack thereof is what caused your menu to go vertical and unstyled.