>>33132404I might be able to answer a couple of these...
>Golurk: flyIt's based on a giant mecha, which I believe are commonly known to fly.
>Gelgyem/Beeheeyem: steel wingThis might have just been an oversight that was left in for some reason. In Gen 4 the TM with that number was Ally Switch, but it became Steel Wing in Gen 5. Presumably it was going to be part of their move set but wasn't corrected when they changed the TM.
>Wailord: selfdestructWailord is supposed to be some kind of blimp whale, so... My best guess would be a Hindenburg reference?
>Marowak/Diglett: aerial aceAerial Ace is named after a legendary sword maneuver in Japanese, which translates as "Swallow Reversal" which is why it is Flying type. Marowak's bone could feasibly be a stand in for a sword, but as for Diglett my best guess is that it's just another "slashing" move like Scratch, Cut, or Slash that Diglett can just learn because it presumably has claws.