You won't be able to access the request params from the bootstrap because it hasn't yet gone through the dispatch/routing process. I think you'd be better served by using a Controller Plugin; performing actions based on the URL is what they do best. Or if you absolutely have to do it in the bootstrap, getRequestUri() or $_GET is available, or you could write a quick script to parse the url yourself.
Edit:
I've done some silly stuff like this in the past before I figured out how plugins work:
/**
* Grab the module name without a request instance
*
* @return string The module name
*/
public static function getModuleName()
{
$uri = ltrim($_SERVER["REQUEST_URI"], "/");
$module = substr($uri, 0, strpos($uri, "/"));
return $module;
}
This would at least give you a module name that you could switch
on in the bootstrap. You should be able to do anything you need with the plugins done correctly though.