Do not edit core files.
.
1.
Assuming you have a registered a custom post type called biblio, you can add and remove “stuff” within your functions.php.
For instance this removes some meta boxes from ‘biblio’
function remove_default_page_screen_metaboxes() {
global $post_type;
remove_meta_box( 'commentstatusdiv','biblio','normal' ); // Comments Metabox
remove_meta_box('commentsdiv','biblio','normal'); // Comments
remove_meta_box( 'trackbacksdiv','biblio','normal' ); // Talkback Metabox
remove_meta_box( 'authordiv','biblio','normal' ); // Author Metabox
}
add_action('admin_menu','remove_default_page_screen_metaboxes');
you can remove and add meta boxes.
http://codex.wordpress.org/Function_Reference/add_meta_box
http://codex.wordpress.org/Function_Reference/remove_meta_box
Reference of all default meta boxes Best Collection of Code for your functions.php file
Read this http://justintadlock.com/archives/2010/04/29/custom-post-types-in-wordpress
and this http://wptheming.com/2010/08/custom-metabox-for-post-type/
2.
By ‘bulk edit’ what exactly do you want to bulk edit? You screenshot shows what is called custom columns, you can add or remove these using the WordPress API
http://codex.wordpress.org/Plugin_API/Action_Reference/manage_posts_custom_column
An example
http://shibashake.com/wordpress-theme/add-admin-columns-in-wordpress