Walker menu $item type and home link troubles

Hi,
I extended the Walker class to get a custom menu option, but some troubles are giving me headache like hell.

This is my walker start_el method:

function start_el(&$output, $item, $depth, $args)
      {

          global $wp_query;

          $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

          $class_names = $value = '';
          $classes = empty( $item->classes ) ? array() : (array) $item->classes;

          $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );

          $class_names = ' class=" '. esc_attr( $class_names ) . ' hvr-bounce-to-top "';

          $output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

          $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
          $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
          $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
          $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';

          $item_output = $args->before;

          $item_output .= '<a'. $attributes .'>';

          $item_output .=
                            $args->link_before .
                            apply_filters( 'the_title', $item->attr_title, $item->ID );

          $item_output .= $args->link_after; 

          $item_output .= '</a>';

          $item_output .= $args->after;

          $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );

    }//start_el

– $item objects
This function doesn’t show any menu link because of $item.
If I treat it like a WP_Post object it works fine. For example if I use:

$attributes .= ( get_permalink( $item->ID ) ) ? ' href="' . esc_attr( get_permalink( $item->ID ) ) .'"' : '';
it works good.
The fact is that the official wordpress codex and lots of link in the internet, doesnt’ treat $item as a WP_object but seems like everything work for them.
Why? How should I treat it?

– home link trouble:
If I can make it working treating $item as a WP_Object, I got problems with the home link anyway.
The walker class doesn’t add the “hvr-bounce-to-top” class to the home link element and I can’t edit it.
It’s like the Walker class can’t see it. I tried to var_dump the $item and $object variables but there’s nothing referred to the home link.
How can I style it? How can I edit the home item?

Thank you in advance for not making my head blowing!