Thanks for the tips people. In order to keep wordpress’ elements and just remove items to stop people playing too much with your design try using the theme_advanced_disable option like so:
/*
* Modifying TinyMCE editor to remove unused items.
*/
function customformatTinyMCE($init) {
// Add block format elements you want to show in dropdown
$init['theme_advanced_blockformats'] = 'p,pre,h1,h2,h3,h4';
$init['theme_advanced_disable'] = 'strikethrough,underline,forecolor,justifyfull';
return $init;
}
// Modify Tiny_MCE init
add_filter('tiny_mce_before_init', 'customformatTinyMCE' );