Re: side entrance or end entrance?
With an end entrance my bees put all of the pollen just inside, then the brood, and most honey goes behind that, then in winter the cluster moves toward the back as honey is consumed.
With an entrance in the middle of the side you could end up with the (starving) cluster at one end and the honey at the other sometime during the winter. If the side entrance were at one end it probably wouldn't matter.
Don't let what might be best prevent you from doing what will work.