Bulk grant views to users

Hello,

I'm completely new to Drupal and trying to learn it, but it's pretty hard. The nodeaccess module is great, but I want to make functionalty for bulk grant for several users. The idea is to have a form grid with several users in columns and nodes and grants in rows. It will look like that:

What I've come to so far:

function table_test_form($form, &$form_state, $node) {
  $form_values = &$form_state['values'];
  if (!$form_values) {
    $form_values = array();
// Get node titles for the first column
        $results = db_query("SELECT DISTINCT title, node.nid
      FROM node_access
      LEFT JOIN node ON node_access.nid = node.nid
      WHERE node.nid < :nid 
      ORDER BY node.nid", array(
        ':nid' => 5,
      ));
    foreach ($results as $noderow) {
      // make an array for every row
      $form_values['noderowid'][$noderow->nid] = array(
        'name' => $noderow->title,
      );
      $current_nid = $noderow->nid;
      //Get users and grants for the current node
      $results_grants = db_query("SELECT uid, name, grant_view
      FROM node_access
      LEFT JOIN users ON uid = gid
      WHERE nid = :nid AND uid < :uid
      ORDER BY uid ", array(
        ':nid' => $current_nid,
        ':uid' => 5,
      ));
    
//      Tried this but didn't work
//      if ($results_grants) {
//        while ($row = $results_grants->fetchAssoc()) {
//          $items_grants[] = array(
//                                    $row['name'] => $row['grant_view']
//          );
//         }
//      }
      $items_grants = $results_grants->fetchAllKeyed(1,2); 
//    add the grants for every user to the node row
      $form_values['noderowid'][$noderow->nid][] = $items_grants;
    }
  }
  
  if (!isset($form_values['noderowid'])) {
    $form_values['noderowid'] = array();
  }

  $noderows = $form_values['noderowid'];

  $form['nid'] = array(
    '#type' => 'hidden',
    '#value' => $node->nid,
  );

  //  the table.
  if (is_array($noderows)) {
    $form['noderowid'] = array('#tree' => TRUE);
    
    foreach ($noderows as $key => $field) {
        if(!isset($form['noderowid'][$key])){
        $form['noderowid'][$key] = array();
    }
    $form['noderowid'][$key]['name'] = array(
        '#type' => 'hidden',
        '#value' => $field['name'],
      );
    $arr = $form['noderowid'][$key];
      //add checkboxes
            foreach ($arr as $nodetitle => $f){
               if($nodetitle!='name'){
                    $form['noderowid'][$key][$nodetitle] = array(
                      '#type' => 'checkbox',
                      '#default_value' => $f[$nodetitle],
                    );
               }
            }
    }
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save Grants'),
  );
  return $form;
}

function theme_table_test_form($variables) {
  $output = '';
  $form = $variables['form'];
  $rows = array();
//get the names of the users and put them in the header
  $uid = 5;
  $sql = "SELECT name FROM users WHERE uid < :uid  ORDER BY uid ASC";
  $result = db_query($sql, array(':uid' => $uid));
  
  if ($result) {
    while ($row = $result->fetchAssoc()) {
      $items[] = array(
	  'data' => t($row['name'])
      );
    }
  }
  // make table.
  unset($rows);
  $noderows = element_children($form['noderowid']);
  if (count($noderows) > 0) {
    $header = $items;
    $rows = array();

    foreach ($noderows as $key) {
      $row = array();

   // first column
      $row[] = $form['noderowid'][$key]['name']['#value'];
   // other columns 
      foreach(array_slice($header, 1) as $usr){
              if(!isset($form['noderowid'][$key][$usr])){
                $form['noderowid'][$key][$usr] = array();
         }
          $row[] = drupal_render($form['noderowid'][$key][$usr]);
      }
      
      $rows[] = $row;
    }
    $output .= theme('table', array('header' => $header, 'rows' => $rows));
  }

  $output .= drupal_render_children($form);

  return $output;
}

It renders the users and nodes names, but not the checkboxes.

I guess it's a pretty bad code and there are too many queries to the database, but I want to just make it work for now.

Please help!