This delay can be caused if you attempt to stream at too high of a resolution. The first thing to do is to try and reduce the resolution you are streaming at (note that this has to be done every time the Pi is rebooted).

If the issue is still there, then you may want to try reducing the JPEG quality and frame rate options on the streaming server configuration page (which is accessible via the link on the video stream page of the web application).

The servos can often make a loud humming sound when they are under substantial load. Usually, this is the case when the arm is fully extended or is attempting to lift a load. If this continues, an extended length of time will consume more battery power and could lower the expected lifetime...