Restricting Q&A to only administrators - any obvious side-effects to this approach?

function remove_unauthorized_questions() {
    global $wp_post_types;

    if ( isset( $wp_post_types[ "question" ] ) && ! current_user_can( "administrator" ) ) unset( $wp_post_types[ "question" ] );
}
add_action( "init", "remove_unauthorized_questions" );

This *seems* to work without issues, there is no debug output to error_log. Any non-administrators simply get redirected back to home page. Perhaps @Hakan can advise me if there's a cleaner solution.

I also tried global $_qa_core; remove_action( array( $_qa_core, "init" ) );, but that didn't work. Not even sure if it would've been better in any way.