In regards to ventilation,drafts are terrible,all openings shouldbeon the
same side of the hive so air will not blow through. A lot of ventilation is
not good ,only a small opening, a slot of maybe 2 inches wide is all that
is nessecary. a bottom opening which is the same size or slightly smaller
is needed in addition to the upper opening. It sounds as though you are
doing well. My suggestion is to tape up all cracks or holes that are not
needed.
Merry Christmas Jerry Fries