um, there should be vacuum and vacuum advance at idle, that is why you remove the hose to check timing. The vacuum should go away when you accelerate, if not this will cause your engine to stumble. If you reattach the vacuum line and your timing doesn't get more advanced at idle then you have a problem.
Nope, it's the opposite. There should be no vacuum signal at idle. Just off idle the vacuum advance nipple gets vacuum as the throttle plates open. If it happened your way, you would have vacuum retard, not advance.