Move Location

If you want to move 2FAS light menu to Settings menu you have to edit src/Menu/Menu.php file located in the plugin directory and change init menu() method to:

public function init_menu() {
	add_options_page(
		$this->menu_title,
		$this->menu_name,
		$this->capability,
		$this->menu_id,
		array( $this, 'init_submenu' )
	);
}

It would be better if this is introduced as an option in your plugin settings. A good example of a plugin that gives users the choice to whether have its own menu or show in settings page is WP External Links.

Probably yes, but as we mentioned in other topic we want to keep plugin simple as possible with security settings only.

Sorry I have to abandon your plugin for cluttering my admin.