How do I Show ALL posts for Catagories and Tags?

Try this (add to your theme’s functions.php):

function my_unlimited_posts_list( $vars ) {
  if ( isset($vars['category_name']) || isset($vars['tag']) )
    $vars['posts_per_page'] = -1;

  return $vars;
}
add_filter( 'request', 'my_unlimited_posts_list' );