Exclude subcategories from the_category

Someone posted this brilliant solution to exclude categories from the_category (placed in functions.php of theme).

function the_category_filter($thelist,$separator=' ') {
	if(!defined('WP_ADMIN')) {
		//list the category names to exclude
		$exclude = array('Something','Something Else','Blah','YAY');
		$cats = explode($separator,$thelist);
		$newlist = array();
		foreach($cats as $cat) {
			$catname = trim(strip_tags($cat));
			if(!in_array($catname,$exclude))
				$newlist[] = $cat;
		}
		return implode($separator,$newlist);
	} else
		return $thelist;
}
add_filter('the_category','the_category_filter',10,2);

Questions:
1. How can I change to this exclude by category ID instead of by category name?
2. Is there way to automatically exclude subcategories/children of the excluded categories? (i.e., without explicity listing all of the subcats)