Hmm, all these tasks seem pretty normal to me :beatsme. I wouldn't do the pile-driving thing, but I've surely seen it done.
My brother once tried the swing thing, not as a young idiot, but as a forty-something y/o shop foreman (idiot). He said before the hoe made a full turn he started screaming for the operator to stop, but the operator couldn't hear him and made several full revolutions,
while on top of a 50' coal stockpile! My brother said it was the most terrifying thing he ever did, the centrifugal force was incredible!
One of the more unusual things I've done:
Not actually an excavator, but a hoe nonetheless, placing pipe a few miles offshore in the Atlantic ocean.