I understand Caravan appearing and being immediately discarded, but why did Aria discard Caravan and Wish rather than Caravan and Dragonling? Dragonling was already on hand and should have been deemed lower cost than Wish.
Dragonling wasn't discarded because it happened to land in the played card slot. Aria keyword effect ignores played card position when looking for target to discard.
Each whirlwind draws a new card before shuffling your hand.
I can't find drawing a new card (cards) in the list in Turn actions help.
Cards that do something with your whole hand tend to disable standard card draw (after keyword effect). This can be seen in Whirlwind code as well.