Couple of issues

1) require custom code and it should be adapted to what you already did. How did you add the listing details on the left? Difficult to tell if there is any easy way without checking your current settings/functions, but this is really beyond support, it is a customization.

What you could do is add it back below the title:

add_action( 'geodir_details_main_content','my_geodir_action_details_slider',30);

function my_geodir_action_details_slider() {

if ( has_post_thumbnail() ) { the_post_thumbnail(array(150, 150));
} 
}

Then style it with css.

2 & 4) Add this in your custom css:

.geodir_lingue > ul {width: 80%;}
ul.geodir-tabs-content li .geodir-company_info .geodir_lingue ul li {display: inline !important;float: left;margin: 0 0 0 4px;padding: 0;width: auto;}
.geodir-tabs-content h2 {display: none;}

Thanks