PB,
 
What you have is what I like to call a "Boomer", be happy it's a sign of
strength and productivity.  They are hanging out to not cause a decrease in
the air flow throughout the hive and to remove their hot bodies from inside.
 The muggy weather you spoke of is the time that you should really see them
hanging out.
 
About adding the supers to the top without an excluder, check to see if the
bees are putting brood in the upper boxes and leaving the lower ones empty.
 They want to lay going up and have to coaxed to lay the lower boxes by
excluder or "honey barrier".  If the lower boxes are not being used it's
really a waste of your equipment (even though you look really great to you
b-keeping buddies) and you could be spreading out the brood-nest into a long
thin (2-4 frames) section in the center of all the boxes.  This makes for a
bunch of manipulation
(possible queen smoosh) later on in the fall to achieve a compact brood-nest.
 I'm not familiar with your area but if you can keep the queen down to the
bottom 2 deeps or a deep and a shallow that's plenty of room to lay eggs and
you always know where she is.  Here in CA alot of hives are running with the
queen confined to a single deep.  That gives room for eggs and keeps the hive
compact for pollination purposes.  Hope that helps.
 
Brian Tassey
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