Not sure what you are referring to. There is still a separate icon for Navigation. You don't have to access it through the Maps icon. Just click Navigation in your Android app list.

As for the crashing, try this. Go into your phone settings, then your Application Manager. Find Maps, then click Clear Cache, Clear Settings, Stop App, then Uninstall Updates. Now go back and reinstall the update again from the Google Play Store and see if that fixes the crashes.