get_the_terms orderby and separator on CPT

Question

I had a problem this morning but finally resolved it. Thing is, now that it is ok, it leaves me with another problem.

Long story short : I created a CPT, added a hierarchical taxonomy to use for my categories, and then created a Buddypress tab to show the posts my users publish in the CPT. Though I finally managed to display the posts with the correct template call, I'm now facing a Categories issue.

Here is the code I'm using at the moment to get the post categories

<?php  
$terms = get_the_terms( $post->ID , 'cptgaleriecat' );
        $sep = ' • ';
                    foreach ( $terms as $term ) {
                        $term_link = get_term_link( $term, 'cptgaleriecat' );
                        if( is_wp_error( $term_link ) )
                        continue;
                    echo '<a href="' . $term_link . '">' . $term->name . '</a>';
                    echo $sep;
                    } 
?>

It works great. I finally get the link to my categories archives. But for some reason, if I use "wp_get_post_terms" to add an array to order my categories by "term_order" so the smaller displays first, it doesn't work. It won't accept "wp_get_post_terms" to retrieve the categories. Is there a way to order the terms with "get_the_terms" or how can I make "wp_get_post_terms" to work?

And the other thing is, for now the separator shows even after the last term. How do I get rid of it?

Thank you for your help!