Remove and change pages label

To change Number of items per page in Screen Options, add this code to functions.php of your theme:

function wpse_modify_screen_option() {
    $number_of_items = 10; // change this to desired value
    $screen = get_current_screen();
    if ( $screen->id != 'edit-page' )
        return;
    $user_id = get_current_user_id();
    if ( $user_id ) {
        update_user_meta( $user_id, 'edit_page_per_page', $number_of_items );   
    }
}

function wpse_screen_option() {
    add_action( 'load-edit.php', 'wpse_modify_screen_option' );
}
add_action( 'admin_menu', 'wpse_screen_option' );

This will change Number of items per page in Screen Options for all users. If you want to do it for selected users only, replace the line:

update_user_meta( $user_id, 'edit_page_per_page', $number_of_items );

with

$users = array( id1,...,idn, ); // replace id1 to idn with user ids
if ( in_array( $user_id, $users ) )
    update_user_meta( $user_id, 'edit_page_per_page', $number_of_items );  

To change the search pages label and remove the numbers of items, make and add the following script ( wpse_search_button.js ) to the root of your theme:

// JavaScript Document
jQuery( document ).ready(function($) {
    $('.displaying-num').css( 'display', 'none' );
    $('#search-submit').val( 'Look for Pages' );
});

Now add this to functions.php:

function wpse_load_admin_js() {
    global $pagenow, $typenow;
    if ( $pagenow == 'edit.php' && $typenow == 'page' ) {
        wp_register_script( 'wpse-search-button-js', get_stylesheet_directory_uri() . '/wpse_search_button.js', array( 'jquery' ), false, true );
        wp_enqueue_script( 'wpse-search-button-js' );   
    }
}
add_action( 'admin_init', 'wpse_load_admin_js' );

This will hide number of items and change ‘Search Pages’ button label to ‘Look for Pages’.