Great Plugin! Some suggestions :)

So I hand coded some php to do what this plugin does and completed it right before I found this handy-dandy tool! It did everything and more!!!

One thing that I did have to hand code and am suggesting for a future release is to have the ability to convert a custom field from plain text to a link in order to edit the item without having to use the drop-down. In my case, I hid all the non-custom fields including the title field. A checkbox as you used for the Sort option should suffice.

Example:
echo'<a href="' . get_edit_post_link( $post->ID, true ) . '" title="' . esc_attr( __( 'Edit this item' ) ) . '">';

Also, to help maximize the real estate in the post list view, you can add a control to set the column widths (percentages, pixels, etc)

Example:

function custom_admin_head() {
    echo '<style type="text/css">';
    echo '.column-field_name_1 { width:20% !important; overflow:hidden }';
    echo '.column-field_name_2 { width:20% !important; overflow:hidden }';
    echo '</style>';
}
add_action('admin_head', 'custom_admin_head');

Remember that even though the above code is placed in the main admin head, it only affects post list views with the specified classes.