wp_trash_post function to only apply to posts, not pages!

You could just add something like:

// Remove 1 point if their post get removed
function deletePointFromUser($post_id) {
  $post = get_post($post_id);

  if( $post->post_type != 'post' ) return;//added code

  $authorid = $post->post_author;
  $currentQPointNumber = get_user_meta($authorid, 'points', true);
  // Delete 1 to the current Point Score
  update_user_meta($authorid, 'points', $currentQPointNumber-1); 
}
add_action('wp_trash_post', 'deletePointFromUser');

Then your point subtraction will only occur if the $post is a post.