I just put the queen cage on the bottom of the hive, screen side up. She was released and I the hive is doing as well as two Langstroths I populated at the same time. With the Langs I suspended the queen cage between two frames. The queens were released OK, but before I came back to remove he cage the girls had built them into comb, so I had to make a bit of a mess of their work. Subject to more experienced hands on this list, I'd say just put the cage on the floor. They ain't going to ignore her.
Great, much easier idea. This time, I had drawn out comb and suspended her between the bars.
As for feeding, we built follower boards with a slat cut out big enough to fit in a Boardman feeder. So the feeder is contained within the hive at the back of the hive. I can take off the cover of the topbar and fill the feeder without disturbing the bees.