If the hive is calmer then you can be fairly certain the hive not only accepted the queen but is well satisfied with her.
As for the slowing down it is possible that a flow might be on the wane but it could also be that they have slowed down inorder to let the queen go to work, not putting the hive into a honey bound situation between introduction of the queen and when she is up to speed. They might have even shifted some of there inside the hive activity to relocating honey inorder to give the queen a more compact laying area--they would do this by delaying the graduation of nurse bees into foragers.