glad to hear it all worked out. Aqueon (formerly All Glass Aquarium) is a good company
their 180's are made with 1/2" glass so glass banging fish are out of the question.
1/2" glass is insanely strong.
its also good that they will, contrary to popular belief, warranty a tank that is NOT on one of their stands. its the competing company (Marineland) that does not.
as far as styro under the tank goes, ironically, styro will void the warranty on Aqueon tanks as they have a floating bottom design and are meant to sit directly on the stand.
sounds like a glass defect to me. a fault of their glass supplier, not necessarily the craftsmanship of Aqueon. I have a 150g from them and love it (runs to check tank lol)