I did a few VIE-AMS segments earlier this year. Sometimes just the taxiing to the terminal from polderbaan took 15-20 minutes, and the flights were on time not that often. I can confirm that the luggage delivery is a pain indeed. Personally, I wouldn't count on making the 19:40 shuttle.
Hampton is ok, but the "airport" in its name is a joke, it's actually quite a drive to the middle of nowhere that is called Hoofddorp. The shuttle stop is not that well sign posted. After you exit the terminal just keep walking to the far right along the bus stops, it's the very last one on the right.