Firefox profile with no caching enabled.
FirefoxProfile profile = new FirefoxProfile();
profile.setPreference("browser.cache.disk.enable", false);
profile.setPreference("browser.cache.memory.enable", false);
profile.setPreference("browser.cache.offline.enable", false);
profile.setPreference("network.http.use-cache", false);
WebDriver driver = new FirefoxDriver(profile);
Similarly profile with alert, prompt etc disabled
profile.setPreference("capability.policy.policynames", "strict") ;
profile.setPreference("capability.policy.strict.Window.alert", "noAccess") ;
profile.setPreference("capability.policy.strict.Window.confirm", "noAccess") ;
profile.setPreference("capability.policy.strict.Window.prompt", "noAccess") ;
