I would always have all the bars in a hive. If you have a follower you could limit them to half of the hive or so (depending on how big half the hive is...). I direct release my queens. Poor queens are an issue and sometimes the bees move next door, but I don't have problems with them leaving the hive unless it's to move next door to another hive which they do whether the queen is caged or not.
http://www.bushfarms.com/beespackages.htm
http://www.bushfarms.com/beespackages.htm
