As for bad URL are you using remote or managed container? Which one? This is not really related to Drone but I believe you have your application/web server server configured to bind to all interfaces. E.g. with JBoss AS7/WF8 -b 0.0.0.0.
You don't want that. Either bind it to particular IP or 127.0.0.1 (localhost). That way you'll get an URL via @ArquillianResource that you'd be able to open in browser.
Note as for running headless, you might also want to setup browser to be phantomjs, no need to have Xvfb ;-)