Best practice for multiple queries on page

On my WordPress site I have three categories ‘moviestar’, ‘interviews’, and ‘movies’.

On a ‘moviestar’ category page that is entitled ‘Angelina Jolie’ (and with a custom variable starname=’Angelina Jolie’), I want to display posts from other categories tagged with ‘Angelina Jolie’.

My Page Example:

Angelina Jolie

(normal page information)

Interviews

query 1 – display linked list of all posts in ‘interviews’ category tagged with ‘Angelina Jolie’

Filmography

query 2 – display linked list of all posts in ‘movies’ category tagged with ‘Angelina Jolie’

NextGen Gallery

query 3 – display all pictures in NextGen Gallery tagged with ‘Angelina Jolie’

So my questions are:

1. How do I query posts in specific categories tagged with Angelina Jolie? Like this?

   global $wpdb;
   $yourCategory = '123';
   $yourTag = 'Angelina-Jolie';
   $querystr = "
               SELECT p.* from $wpdb->posts p, $wpdb->terms t, $wpdb->term_taxonomy tt, $wpdb->term_relationships tr, $wpdb->terms t2, $wpdb->term_taxonomy tt2, $wpdb->term_relationships tr2
               WHERE p.id = tr.object_id
               AND t.term_id = tt.term_id
               AND tr.term_taxonomy_id = tt.term_taxonomy_id
               AND p.id = tr2.object_id
               AND t2.term_id = tt2.term_id
               AND tr2.term_taxonomy_id = tt2.term_taxonomy_id
               AND (tt.taxonomy = 'category' AND tt.term_id = t.term_id AND t.slug = '$yourCategory')
               AND (tt2.taxonomy = 'post_tag' AND tt2.term_id = t2.term_id AND t2.slug = '$yourTag')
               ";
   $pageposts = $wpdb->get_results($querystr, OBJECT);
   if ($pageposts):
       foreach ($pageposts as $post):
           setup_postdata($post);
           // do regular WordPress Loop stuff in here
       endforeach;
   else :
       // nothing found
   endif;
   

2. How do I modify the above to query multiple categories and store which category the post is in?

3. Does it make sense that I will query once on the page and then use a PHP loop to echo out the information under each heading? Something like…

   while(($row=mysql_fetch_array($result))&&($row['cat']=='845')){
     echo "<li><a href='".$row['url']."'>". $row['post_title'] . "</a></li>";
   

4. Would it be better to abandon using WordPress functions and queries and instead query the db directly using normal php?

I really need some advice or a good example. I’m using WordPress 3.3.2

I have read the following but I just don’t get it yet:

http://www.borishoekmeijer.nl/show-related-posts-using-custom-taxonomy/
https://stackoverflow.com/questions/8563136/wordpress-query-filtering-by-custom-field-tag-and-category