If you missed any queen cells be prepared for the possiblity of a swarm, new queen or not. In some hives where the creation of queen cells are done on a staggered basis--it is not unusual to have a swarm every time a different age of queen emerges. I've seen hives that have swarmed as many as five times in 3 weeks. Of course the last swarm is about the size of a baseball and the swarming decimated the hive.
I'm glad the vanilla worked, it is a technique that has become labled as an old wives tale just like many folk medicine remedies.
Extra room is a good way to curb the swarm urge. In a pinch just replacing a few frames with foundation can head off a building swarm situation. Avoid overcrowding and you can reduce swarming by 50%.