(9) Never before did an alliance have its own air force (NATO E-3 planes officially belong to Luxembourg, but they really are NATO's planes)
(10) Alliances didn't use to routinely deploy symbolic force detachments into areas of crisis. Nor was such behaviour expected, much less without any such obligation in the treaty text.
(11) Permanent ("forward") deployment of forces in allied states wasn't typical of alliances at all prior to NATO (and the Warsaw Pact). The current "normalcy" of forward deployed forces is a leftover from post-WW2 occupation forces - path dependency led us here. Previously, permanent military detachments in allied countries were typical of a hegemon-client relationship between the allies (such as Nazi Germany and Romania 1939/41, or Sparta and Thebes etc.) only.
I suppose that modern Europeans aren't really aware how atypical NATO is as an alliance. Seemingly self-evident features of NATO have hardly ever or never before been observed in other alliances.